WASHINGTON (CNN) -- Frustrated U.S. lawmakers from both sides of the aisle slammed the Bush administration Thursday for an Iran policy they charged lacks direction and has failed to curb Iran's nuclear ambitions.
At a joint hearing Thursday, lawmakers criticized President Bush's approach to Iran's nuclear program.
In an often contentious joint hearing, House committees dealing with foreign affairs, the Middle East, terrorism, nonproliferation and trade said the United States has not imposed strict enough sanctions against Iran to stop it from advancing its nuclear program.
"Within the next two years, there is a real possibility that Iran will have the means to make an atomic bomb," said Rep. Gary Ackerman, D-New York. "The reason for this awful truth is that they wanted it more than we wanted to stop them."
"Future generations of Americans will neither understand nor forgive this appalling foreign policy failure," he added
Despite three U.N. resolutions imposing sanctions against Iran and an international campaign to put financial pressure on Iran, Tehran continues to develop its nuclear program.
Last week, Iranian President Mahmoud Ahmadinejad said that 6,000 new centrifuges will become operational at Iran's uranium-enrichment plant in Natanz over the coming year, a claim the United States cannot confirm.
Iran insists its nuclear program is for peaceful purposes. But following a meeting Thursday with British Prime Minister Gordon Brown, President Bush said it is "naive" to think Iran would not be able to transfer nuclear enrichment into a weapons program.
The United States, along with Britain, France, China, Russia and Germany, has been following a "dual track strategy" with Iran, which includes tightening sanctions on the regime while offering incentives if Iran suspends its enrichment activities.
Jeffrey Feltman, the State Department's principal deputy assistant secretary for the Middle East, told the House committees there was some evidence the approach was working, noting that firms and banks around the world are curtailing business with Iran because of the risks involved.
"Our hope is that Iran's calculus will change as this incremental pressure increases," Feltman said.
Ackerman, chairman of the House Foreign Affairs Subcommittee on the Middle East and South Asia, countered that "having a policy of hope is horse dung," charging the sanctions have not changed Iran's behavior.
"No evidence is there at all that progress is being made because you measure progress in altered behavior," he said.
Lawmakers also criticized the Bush administration's inability to curb Iran's growing influence throughout the broader Middle East, questioning whether a broader engagement on all of the issues would be prudent.
When Bush leaves office, "Iran will be a stronger nation than when he took office; Iran will be far closer to becoming a nuclear power than it was when Mr. Bush took office; and Iran, unfortunately, plays a much more prominent role in supporting the financial terror network in the region and throughout the world than it did ... before Mr. Bush took office," said Rep. Robert Wexler, D-Florida. "So on almost any litmus test with respect to Iran, the Bush administration, in my view, has been an utter failure."
Rep. Mike Pence, R-Indiana, agreed. "It seems like everywhere we turn, Iranian mischief and malevolence is not far behind," he said.
In addition to supporting terror networks like Hamas, Hezbollah and the Taliban, the United States accuses of Iran of trying to destabilize the governments in Lebanon and Iraq, where the U.S. government says that Iran provides Shiite extremist groups with explosives that kill U.S. soldiers and diplomats.
On Thursday, Secretary of State Condoleezza Rice called on Iran to end "actions that interfere in Iraq's affairs, undermine Iraq's government and harm or murder innocent Iraqis."
While Iran's influential role in neighboring Iraq is expected to be at the top of Rice's agenda Tuesday at the ministerial meeting of Iraq's neighbors in Kuwait, she said Thursday she had no plans to meet with the Iranians.
Rice said she would press Iraq's Arab neighbors to shield it from Iran's "nefarious influences."
Iranian Foreign Minister Manouchehr Mottaki is expected to be at next week's meeting. Rice and Mottaki have exchanged pleasantries at previous meetings, but have not had substantive talks.
Ryan Crocker, the U.S. ambassador to Iraq, has held several rounds of talks with his Iranian counterpart to discuss the security situation in Iraq, but the talks have not produced meaningful results. E-mail to a friend