U.S. Secretary of State John Kerry is now being accused of bowing to the Iranian regime when he said that the Obama government could and would help Iran bypass current visa restrictions passed by Congress.

In a Dec.19, 2015 letter sent to his Iranian counterpart, Foreign Minister Mohammad Javad Zarif, Kerry suggested that the Obama administration could waive the present visa restrictions for Iranian government officials.

"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,'' Kerry said, according to Fox News.

Kerry also reportedly assured his counterpart that the U.S. would "adhere to the full measure of our commitments."

"To this end, we have a number of potential tools available to us, including multiple entry 10-year business visas, programmes for expediting business visas, and the waiver authority provided under the new legislation,'' he wrote.

The Secretary of State was referring to the U.S. visa waiver programme, where changes have been made including stricter guidelines on people travelling from Iran, Iraq, Syria and Sudan, all of whom cannot enter the U.S. without a visa.

Tehran officials had complained about the new changes and accused the U.S. of flouting the nuclear agreement, reports said.

"Definitely, this law adversely affects economic, cultural, scientific and tourism relations," Iran's Deputy Foreign Minister Abbas Araghchi was quoted by state TV as saying.

"This contradicts the nuclear deal," Iranian Parliament Speaker Ali Larijani also noted.

Republicans claimed that Kerry's assurance to the Iranian regime raises concerns that the U.S. may be yielding to Iran's complaints while avoiding to punish Tehran for its own potential violations.

"Instead of undermining congressional intent regarding the visa waiver programme, the White House should instead focus on Iran's repeated violations of the U.N. Security Council's bans on missile tests," House Majority Leader Kevin McCarthy, R-California, said in a statement.

"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,'' he stressed.

House Foreign Affairs Committee chair Ed Royce also told Fox News that the White House needs to be holding the rogue nation accountable "for its recent missile tests, its continued support for terrorism, and its wrongful imprisonment of Americans" instead of pacifying Iran.

The Republicans emphasised that the legislation's intent was "to strengthen security and keep the American people safe from terrorism and from foreign travelers who potentially pose a threat to our homeland'' and not to allow the administration "to grant a blanket waiver to travellers from Iran in order to facilitate the implementation of the Iran deal."