Kanaani also said two of the Iranians being released would return to Iran while two would stay in the US at their request. One detainee would join his family in a third country, he added.

The deal will remove a major irritant between the US, which brands Tehran a state sponsor of terrorism, and Iran, which calls Washington the “Great Satan”.

But the countries remain deeply divided on other issues ranging from Iran’s nuclear programme and its influence around the region to US sanctions and America’s military presence in the Gulf.

A senior US administration official said the deal did not change Washington’s adversarial relationship with Tehran, but the door was open for diplomacy on Iran’s nuclear programme.

“If we see an opportunity, we will explore it but right now, I’ve really nothing to talk about,” the official said, speaking on condition of anonymity.

US Secretary of State Antony Blinken said on Monday that he spoke to the US citizens.

“It’s very good to be able to say that our fellow citizens are free,” Blinken told reporters in New York.

“I can tell you that it was for them, for me, an emotional conversation.”

“President Biden has demonstrated that he’s prepared to make tough and difficult decisions,” Blinken said.

“I have no higher priority. The president has no higher priority than making sure that Americans who are unjustly detained anywhere can come home and we will continue that work.”

Blinken said that the prisoner swap was a “different track” from other issues with Iran such as its contested nuclear programme.

“We’ve been focused on working independently to bring these Americans home, so it doesn’t speak to anything else in the relationship,” he said.

02:12

Daughter of Iranian-American environmentalist jailed in Iran fears US will not be able to free him

Daughter of Iranian-American environmentalist jailed in Iran fears US will not be able to free him

Qatar, a tiny but hugely wealthy Gulf Arab energy producer, has sought to raise its global profile, hosting the football World Cup last year and carving out a role in international diplomacy. The Sunni Muslim nation hosts a big US military base but has also forged close ties with Shiite Muslim Iran.

Doha hosted at least eight rounds of talks with Iranian and US negotiators sitting in separate hotels, speaking via shuttle diplomacy, a source previously said.

The transfer of Iran’s funds under the agreement has drawn criticism from US Republicans who say Biden, a Democrat, is in effect paying a ransom for US citizens.

The White House has defended the deal.

China and Iran pledge cooperation ahead of Brics summit

The US dual citizens to be released include Siamak Namazi, 51, and Emad Shargi, 59, both businessmen, and Morad Tahbaz, 67, an environmentalist who also holds British nationality. They were released from prison and put under house arrest last month.

A fourth US citizen was also released into house arrest, while a fifth was already under house arrest. Their identities have not been disclosed.

Iranian officials have named the five Iranians to be released by the US as Mehrdad Moin-Ansari, Kambiz Attar-Kashani, Reza Sarhangpour-Kafrani, Amin Hassanzadeh and Kaveh Afrasiabi. Two Iranian officials previously said that Afrasiabi would remain in the United States but had not mentioned others.

Ties between Washington and Tehran have been boiling since Donald Trump, a Republican, pulled the US out of a nuclear deal between Iran and global powers when he was president in 2018. Reaching another nuclear deal has gained little traction since, as Biden prepares for the 2024 US election.

As a first step in the deal, Washington waived sanctions to allow the transfer of the US$6 billion in Iranian funds from South Korea to Qatar. The funds were blocked in South Korea, normally one of Iran’s largest oil customers, when Washington imposed sweeping financial sanctions on Tehran and the cash could not be transferred.

Additional reporting by Agence France-Presse