Our live coverage has ended. Scroll through the posts below to see how the day unfolded.
Sen. Ron Wyden, a Democrat from Oregon, accused President Trump of assembling an "enemies list" of critics through his efforts to strip a half-dozen national security officials of their security clearances.
Trump is considering revoking the security clearances of several former national security officials who have been publicly critical of him, White House press secretary Sarah Sanders announced at today's press briefing.
"As I listen to this, it sounds to me like Donald Trump is talking about building an enemies list," Wyden said on CNN's "Erin Burnett OutFront."
The term "enemies list" harkens back to the tenure of President Richard Nixon, who had his aides keep an "enemies list" of politicians, journalists and entertainers who Nixon felt had wronged him.
Watch the moment:
Iranian Foreign Minister Mohammad Javad Zarif took to Twitter Monday, following President Trump’s explosive threat to Iran.
Trump's threat: Trump sent a threatening Twitter message to Iranian President Hassan Rouhani on Sunday night. It read:
Earlier Monday, White House press secretary Sarah Sanders told reporters that Trump was responding to comments made by Iran.
Iran's president had warned Trump not to "play with the lion's tail, because you will regret it eternally." Rouhani also floated the possibility of a peaceful relationship with the US, in remarks reported by Iranian state media.
Republican Rep. Scott Taylor pushed back on the White House threats today to revoke a number of former intelligence officials' security clearances.
Taylor said even though he thinks remarks made by some former US intelligence officials are "nasty" and "counterproductive," "it’s free speech."
"I’m troubled by it, it’s not what we need to be doing — no question about it,” he said.
President Trump has yet to decide whether he intends to actually go ahead with the revocation of security clearances, a senior administration official said tonight.
The official added Trump is “more than comfortable with how this whole discussion is playing out.”
The officials said that even talking about revoking security clearances is just “another way to go after old Obama officials” he thinks have been unfair to him.
So for all of the discussion of how this is another unprecedented move from Trump and for all of the hand-wringing from experts, the White House believes today’s animated media coverage of this is just fine.
“It’s a new way to make the deep state argument,” the official said, which the President believes fires up his base.
Republican Sen. Marco Rubio told CNN's Wolf Blitzer tonight that he's still looking into the pros and cons of revoking certain former intelligence officials of their security clearances.
"These clearances exist to further the national security of the United States, and that's the only people that are entitled and need to have it," the Florida lawmaker said.
He said while security clearances were granted to former US intelligence officials in the past, "we're in a different time and these sorts of things are always open to reexamination."
He added: "I just want to be clear, no one is entitled to this stuff. They're not actively, every single day contributing to our national security. They provided a service to our country in the past."
Republican Sen. Rand Paul tweeted Monday that he asked President Donald Trump to revoke the security clearance of former CIA Director John Brennan, who criticized Trump's performance last week at the Helsinki summit with Russian President Vladimir Putin.
In an unusual move, Paul wrote Monday morning that he would meet with Trump to discuss allegations that Brennan is "monetizing his security clearance" and "making millions of dollars divulging secrets to mainstream media."
Read one of Paul's tweets:
White House press secretary Sarah Sanders later confirmed in a press briefing that Trump is considering stripping Brennan and a number of other former national security officials of their clearances.
A person familiar with former FBI Director James Comey's departure from government tells CNN that Comey was “read out” of his clearances when he left -- just like when any employee leaves the government.
This follows White House press secretary Sarah Sanders' briefing where she said President Trump was considering revoking Comey's security clearance, alongside other former officials.
Vice President Pence is speaking at an event in Philadelphia this afternoon, where said Trump has "put Iran on notice," adding “we will not tolerate threats against the United States of America."
Here's more from his speech:
“While the Iranian people have been standing up in the streets, standing up to their dictators in Tehran, this President put Iran on notice. He cancelled the Iran Nuclear Deal, and as he made clear last night, we will no longer tolerate Iran sowing violence or terror across the world. And we will not tolerate threats against the United States of America.”