President Barack Obama addresses American University's School of International Service in Washington, District of Columbia, U.S., on Wednesday, Aug. 5, 2015. The speech focused on the Iran nuclear deal being debated in Congress.
Pete Marovich/Bloomberg/Getty Images
President Barack Obama addresses American University's School of International Service in Washington, District of Columbia, U.S., on Wednesday, Aug. 5, 2015. The speech focused on the Iran nuclear deal being debated in Congress.
Now playing
01:36
Kerry on Iran deal: 'We'll continue to persuade'
Iranian women chant slogans during an anti-US demonstration outside the former US embassy headquarters in the capital Tehran on May 9, 2018. - Iranians reacted with a mix of sadness, resignation and defiance on May 9 to US President Donald Trump's withdrawal from the nuclear deal, with sharp divisions among officials on how best to respond.
For many, Trump's decision on Tuesday to pull out of the landmark nuclear deal marked the final death knell for the hope created when it was signed in 2015 that Iran might finally escape decades of isolation and US hostility. (Photo by ATTA KENARE / AFP)        (Photo credit should read ATTA KENARE/AFP/Getty Images)
ATTA KENARE/AFP/AFP/Getty Images
Iranian women chant slogans during an anti-US demonstration outside the former US embassy headquarters in the capital Tehran on May 9, 2018. - Iranians reacted with a mix of sadness, resignation and defiance on May 9 to US President Donald Trump's withdrawal from the nuclear deal, with sharp divisions among officials on how best to respond. For many, Trump's decision on Tuesday to pull out of the landmark nuclear deal marked the final death knell for the hope created when it was signed in 2015 that Iran might finally escape decades of isolation and US hostility. (Photo by ATTA KENARE / AFP) (Photo credit should read ATTA KENARE/AFP/Getty Images)
Now playing
01:39
How will US pulling out of deal impact Iranians?
CNN
Now playing
01:07
Trump announces withdrawal from Iran deal
Photo Illustration: Getty/Shutterstock/CNNMoney
Now playing
01:55
Breaking down Trump's decision to leave the Iran deal
Iranian lawmakers burn two pieces of papers representing the U.S. flag and the nuclear deal as they chant slogans against the U.S. at the parliament in Tehran, Iran, Wednesday, May 9, 2018. Iranian lawmakers have set a paper U.S. flag ablaze at parliament after President Donald Trump's nuclear deal pullout, shouting, "Death to America!". President Donald Trump withdrew the U.S. from the deal on Tuesday and restored harsh sanctions against Iran. (AP Photo)
AP
Iranian lawmakers burn two pieces of papers representing the U.S. flag and the nuclear deal as they chant slogans against the U.S. at the parliament in Tehran, Iran, Wednesday, May 9, 2018. Iranian lawmakers have set a paper U.S. flag ablaze at parliament after President Donald Trump's nuclear deal pullout, shouting, "Death to America!". President Donald Trump withdrew the U.S. from the deal on Tuesday and restored harsh sanctions against Iran. (AP Photo)
Now playing
00:38
Watch: US flag set alight in Iran's parliament
France Nuclear Fallout_00005926.jpg
France Nuclear Fallout_00005926.jpg
Now playing
02:59
Renewed Iran sanctions may hurt France as well
U.S. President Donald Trump answers questions from the press during a meeting with former U.S. Secretary of State Henry Kissinger in the Oval Office October 10, 2017 in Washington, DC. Trump answered a range of questions during the portion of the meeting that was open to the press, including queries on Secretary of State Rex Tillerson.
Win McNamee/Getty Images North America/Getty Images
U.S. President Donald Trump answers questions from the press during a meeting with former U.S. Secretary of State Henry Kissinger in the Oval Office October 10, 2017 in Washington, DC. Trump answered a range of questions during the portion of the meeting that was open to the press, including queries on Secretary of State Rex Tillerson.
Now playing
02:04
Years of Trump panning the Iran deal
ISFAHAN, IRAN - MARCH 30:  A worker walks inside of an uranium conversion facility March 30, 2005 just outside the city of Isfahan, about 254 miles (410 kilometers), south of capital Tehran, Iran. The cities of Isfahan and Natanz in central Iran are home to the heart of Iran's nuclear program. The facility in Isfahan makes hexaflouride gas, which is then enriched by feeding it into centrifuges at a facility in Natanz, Iran. Iran's President Mohammad Khatami and the head of Iran's Atomic Energy Organisation Gholamreza Aghazadeh is scheduled to visit the facilities. (Photo by Getty Images)
Getty Images/Getty Images Europe/Getty Images
ISFAHAN, IRAN - MARCH 30: A worker walks inside of an uranium conversion facility March 30, 2005 just outside the city of Isfahan, about 254 miles (410 kilometers), south of capital Tehran, Iran. The cities of Isfahan and Natanz in central Iran are home to the heart of Iran's nuclear program. The facility in Isfahan makes hexaflouride gas, which is then enriched by feeding it into centrifuges at a facility in Natanz, Iran. Iran's President Mohammad Khatami and the head of Iran's Atomic Energy Organisation Gholamreza Aghazadeh is scheduled to visit the facilities. (Photo by Getty Images)
Now playing
01:20
Explaining the Iran nuclear deal
CNN
Now playing
00:47
John Kerry wants Trump to stay in Iran deal
Now playing
01:47
Rouhani: Pity if rogue newcomers end the deal
President Donald Trump delivers a statement on the Iran nuclear deal from the Diplomatic Reception Room of the White House, Tuesday, May 8, 2018, in Washington. (AP Photo/Evan Vucci)
Evan Vucci/AP
President Donald Trump delivers a statement on the Iran nuclear deal from the Diplomatic Reception Room of the White House, Tuesday, May 8, 2018, in Washington. (AP Photo/Evan Vucci)
Now playing
02:42
Trump: US withdrawing from Iran deal
WASHINGTON, DC - AUGUST 04:  Former CIA Director Gen. Michael Hayden (Ret.) testifies during a hearing before Senate Armed Services Committee August 4, 2015 on Capitol Hill in Washington, DC. The committee held a hearing on the Joint Comprehensive Plan of Action (JCPOA) and the military balance in the Middle East.  (Photo by Alex Wong/Getty Images)
Alex Wong/Getty Images North America/Getty Images
WASHINGTON, DC - AUGUST 04: Former CIA Director Gen. Michael Hayden (Ret.) testifies during a hearing before Senate Armed Services Committee August 4, 2015 on Capitol Hill in Washington, DC. The committee held a hearing on the Joint Comprehensive Plan of Action (JCPOA) and the military balance in the Middle East. (Photo by Alex Wong/Getty Images)
Now playing
02:12
Ex-CIA chief: Netanyahu's findings are old news
Israeli Prime Minister Benjamin Netanyahu presents material on Iranian nuclear weapons development during a press conference in Tel Aviv, Monday, April 30 2018. Netanyahu says his government has obtained "half a ton" of secret Iranian documents proving the Tehran government once had a nuclear weapons program. Calling it a "great intelligence achievement," Netanyahu said Monday that the documents show that Iran lied about its nuclear ambitions before signing a 2015 deal with world powers. (AP Photo/Sebastian Scheiner)
Sebastian Scheiner/AP
Israeli Prime Minister Benjamin Netanyahu presents material on Iranian nuclear weapons development during a press conference in Tel Aviv, Monday, April 30 2018. Netanyahu says his government has obtained "half a ton" of secret Iranian documents proving the Tehran government once had a nuclear weapons program. Calling it a "great intelligence achievement," Netanyahu said Monday that the documents show that Iran lied about its nuclear ambitions before signing a 2015 deal with world powers. (AP Photo/Sebastian Scheiner)
Now playing
02:15
Responses in wake of Netanyahu's Iran speech
Josh Rogin 01
CNN
Josh Rogin 01
Now playing
01:44
Takeaways from Netanyahu's Iran remarks
pool
Now playing
01:31
Trump: Iran under control of fanatical regime
nikki haley us evidence against iran weapons sot _00013621.jpg
nikki haley us evidence against iran weapons sot _00013621.jpg
Now playing
02:00
Haley: This is concrete evidence against Iran

Story highlights

Barbara Mikulski of Maryland became the 34th senator to back Obama's Iran nuclear deal

That gives Obama a veto-proof coalition to protect the deal from being blocked by Congress

Secretary of State John Kerry is pushing for more support of the deal in a speech Thursday

(CNN) —  

In a major victory for President Barack Obama, Democratic Sen. Barbara Mikulski of Maryland announced support for the Iran nuclear deal Wednesday, providing the White House the votes it needs to prevent Republicans from scuttling the agreement.

The announcement means that at least 34 senators – the number required by the Constitution to sustain a veto – will back Obama’s expected veto of a Republican resolution to disapprove of the deal. Mikulski is retiring at the end of her term.

While majorities of both the GOP-controlled House and Senate are poised to vote against the agreement, supporters of the multinational accord that aims to curb Iran’s nuclear weapons program are also hoping to get the 41 votes needed to filibuster the bill and prevent it from even getting to a final vote in the Senate.

Secretary of State John Kerry said the administration will continue to try and push support for the deal past the 34 votes they now have “until the last moment.”

“Thirty-four votes are obviously enough votes for the president’s veto to be upheld,” Kerry told CNN’s Christiane Amanpour. “That is not satisfactory for us. We do want to try to go further. We’ll continue to persuade.”

That prospect upsets some Republicans who believe the historic agreement deserves a final up-or-down vote.

Related: Pro-Iran deal Sen. Chris Coons wants up-or-down vote

Nearly all Republicans have come out against the agreement, arguing it sets up weak standards for international inspectors to monitor whether Iran is complying with the agreement and would allow Iran to build nuclear weapons in a few years.

But only two Democratic senators – Chuck Schumer of New York and Bob Menendez of New Jersey – have announced they oppose it. The Senate’s 54 Republicans would need four more Democrats to join them in opposing the deal to end the filibuster and send the bill disapproving of the deal for a vote.

The agreement, which took years for the so-called P5+1 – the U.S., U.K., France, Germany, China and Russia – to broker, has been the subject of intensive lobbying by both sides. Ultimately, opponents’ multimillion-dollar campaign failed to resonate with enough of the Democratic lawmakers it was targeting.

Votes are expected after lawmakers return from a summer recess next week but before Sept. 17, the statutory deadline for Congress to act on the deal. But GOP leaders have not announced when those votes will take place.

House Speaker John Boehner’s spokesman Cory Fritz said the White House shouldn’t be celebrating.

“Forcing a bad deal, over the objections of the American people and a majority in Congress, is no win for President Obama. The White House may have convinced just enough Democrats to back an agreement that legitimizes Iran’s nuclear program, trusts the regime to self-inspect and offers amnesty to terrorists, but this deal is far from being implemented,” Fritz said.

Read more: What is the Iran nuclear deal?

The administration only needs one chamber to sustain its veto in order for the Iran deal to go through. House Democratic leadership aides are confident that they also have enough votes in the House to uphold a veto.

The Iran deal has been a charged topic in the 2016 presidential race and GOP, candidate Sen. Marco Rubio of Florida, a member of the Senate Foreign Relations Committee, was the first in the field to react to the 34th vote.

“When I’m President, we won’t just reverse President Obama’s dangerous Iran deal. We will increase sanctions on Iran,” Rubio tweeted Wednesday.

Vice President Joe Biden, meanwhile, tweeted that “The #IranDeal is the best available option to block Iran from a bomb. It is in our national security interests.”

The administration is clear it will continue to sell the Iran deal to the public as it looks to bolster the number of votes in favor of the deal and sway a divided public.

Kerry took the administration’s sales pitch to Philadelphia on Wednesday, making a speech at the National Constitution Center to drum up further support for the deal.

“Rejecting this agreement would not be sending a signal of resolve to Iran,” he told the audience there, “it would be broadcasting a message so puzzling most people across the globe would it find impossible to comprehend.”

Kerry also took aim at the deal’s opponents, dispelling what he called “myths” and “false information that has been circulating about the proposal on which Congress will soon vote.”

“The outcome [of that vote],” Kerry said, “will matter as much as any foreign policy decision in recent history. “

And Kerry is now bringing his appeal to each member of congress, sending letters to all their offices on Wednesday morning ahead of the speech.

“We share the concern expressed by many in congress regarding Iran’s continued support for terrorist proxy groups throughout the region,” he wrote in that letter, “it’s propping up of the Assad regime in Syria, its efforts to undermine the stability of its regional neighbors and the threat it poses to Syria.”

“We have no illusion that this behavior will change following implementation of the JCPOA,” he added.

Kerry also reaffirmed Obama’s pledge that Israel’s security is “sacrosanct,” adding the administration is prepared to further strengthen” the U.S.-Israel security relationship with talks on a new 10-year memorandum of understanding on Aid which Kerry said would “cement for the next decade our unprecedented levels of military assistance.”

The U.S. has already promised Israel Increased cooperation on missile defense and other capabilities for Israel, as well as increased military aid and other assistance to Gulf States.

Kerry said the Administration would work with Congress on legislation to appropriate funding for these measures and resources.

He added that while the administration believes the Iran deal would deny Iran pathway to a nuclear weapon, the U.S. would “continue to provide Israel and our GCC partners the “robust assistance and support they need to combat Iranian destabilizing activity in the region.”

In his speech, Kerry also indicated the administration could use the deal as a launching point for other discussions with Iran, including talks to free the Americans currently jailed or missing in Iran – Amir Hekmati, Saaed Abedini, Jason Rezaian, and Robert Levinson.

“We will do everything we can to see that our citizens are able to return safely to where they belong – at home and with their families” said Kerry.