Republicans on Monday blasted Secretary of State John Kerry for suggesting in a letter to his Iranian counterpart that the administration could help the country get around new visa restrictions passed by Congress.

“Instead of bending over backwards to try to placate the Iranian regime, the White House needs to be holding it accountable for its recent missile tests, its continued support for terrorism, and its wrongful imprisonment of Americans,” House Foreign Affairs Committee Chairman Ed Royce, R-Calif., said in a statement to FoxNews.com.

At issue are tightened security requirements for America’s visa waiver program, which allows citizens of 38 countries to travel to the U.S. without visas. Under changes in the newly signed spending bill, people from those countries who have traveled to Iran, Iraq, Syria and Sudan in the past five years must now obtain visas to enter the U.S.

Top Tehran officials, however, complained the changes violate the terms of the nuclear deal, which says the U.S. and other world powers will refrain from any policy intended to adversely affect normalization of trade and economic relations with Iran.

Kerry responded to these concerns in a Dec. 19 letter to his Iranian counterpart, Mohammad Javad Zarif -- and suggested the administration could simply bypass the rules for Iran. 

“I am also confident that the recent changes in visa requirements passed in Congress, which the Administration has the authority to waive, will not in any way prevent us from meeting our [nuclear deal] commitments, and that we will implement them so as not to interfere with legitimate business interests of Iran,” he said.  

Kerry’s letter to Zarif assured that the U.S. would “adhere to the full measure of our commitments.” As for changes to the visa program, Kerry floated several alternative options for easing any impact on Iran – including waiving the new requirements.

“To this end, we have a number of potential tools available to us, including multiple entry ten-year business visas, programs for expediting business visas, and the waiver authority provided under the new legislation,” he wrote.

The legislation indeed includes a provision allowing the Homeland Security secretary to waive the requirements if the secretary determines this “is in the law enforcement or national security interests of the United States.”

But House Majority Leader Kevin McCarthy, R-Calif., voiced concern on Monday that Kerry was proposing a “blanket” waiver to accommodate Iran’s complaints. He said that is not Congress’ intent.

“Contrary to what the Secretary of State seems to be saying to Iranian Foreign Minister Javad Zarif, it was not and has never been Congress’s intent to allow the Administration to grant a blanket waiver to travellers from Iran in order to facilitate the implementation of the Iran deal,” he said in a statement.

McCarthy said the point of the legislation was to strengthen security and “keep the American people safe from terrorism and from foreign travelers who potentially pose a threat to our homeland.”

Kerry’s assurances also raised concerns that the U.S. may be backing down to Iran’s complaints while at the same time reluctant to punish Tehran for its own potential violations.

“Instead of undermining Congressional intent regarding the visa waiver program, the White House should instead focus on Iran’s repeated violations of the U.N. Security Council's bans on missile tests,” McCarthy said. “Iran’s unwillingness to follow these international agreements should be a red flag that the Iran nuclear deal isn’t worth the paper it is written on.”

Omri Ceren, with the Washington, D.C.-based Israel Project, also told The Washington Free Beacon, “According to the Obama administration’s latest interpretation, the nuclear deal allows Iran to test ballistic missiles in violation of international law, but does not allow Congress to prevent terrorists from coming into the United States.”

The same article noted that the State Department official in charge of implementing the nuclear agreement warned Congress last week that the new visa rules “could have a very negative impact on the deal.”

Indeed, Kerry’s letter came as top-ranking Iranian officials accused the U.S. of flouting the nuclear agreement.

Iran’s Deputy Foreign Minister Abbas Araghchi said Sunday that the change “contradicts” the nuclear deal.

"Definitely, this law adversely affects economic, cultural, scientific and tourism relations,” Araghchi was quoted by state TV as saying.

Iranian Parliament Speaker Ali Larijani made similar comments.

Asked about Kerry’s assurances at Monday’s daily briefing, State Department spokesman John Kirby said the secretary made clear they would “implement this new legislation so as not to interfere with legitimate business interests of Iran.”

Kirby said the law would be followed, but there are a “number of potential tools” to ensure this does not violate the nuclear deal. As for the DHS waiver authority, he said it’s too soon to say “if and when” that might be used.

The Kerry letter initially was obtained and published by the National Iranian American Council.

The State Department confirmed the document’s authenticity on Monday.

FoxNews.com’s Judson Berger and The Associated Press contributed to this report.