Washington, DC - Republicans have denounced Monday's prisoner swap between the United States and Iran, saying that the deal provides an incentive for Tehran to detain more Americans in future.

Officials in the administration of US President Joe Biden, however, hailed the release of the five US citizens from Iranian custody, adding that they would soon be reunited with their families.

Five Iranian prisoners in the US were likewise returned to their home country.

The Qatar-brokered agreement also saw the unfreezing of $6bn in Iranian funds formerly held in South Korea. Prior to Monday's deal, the funds could not be transferred due to US sanctions against Iran.

Here's how Republicans and Democrats reacted to the agreement.

A plane carrying five American prisoners released by Iran as part of a high-profile prisoner exchange has landed in the Qatari capital Doha, before the former detainees are expected to then fly on to the United States.

The former detainees walked off the plane on Monday onto the tarmac at Doha International Airport after arriving from Tehran. They were greeted by both US and Qatari officials.

Al Jazeera's Imran Khan, reporting from the airport, said that the former prisoners were not expected to spend long in Qatar, and would soon be on their way home to the US.

"There's a visible sense of actual relief," Khan said. "Its all smiles now."

Two of the five Iranians imprisoned by the US have already arrived in the Gulf state, before they transit on to Iran. The three other released Iranians have decided against returning to Iran, with two staying in the US, and one going on to a third country.

The agreement between the US and Iran has also seen $6bn in Iranian assets held in South Korea unfrozen, triggering the prisoner exchange.

US President Joe Biden welcomed the return of the five citizens and thanked allies for helping secure their release.

"Siamak Namazi, Morad Tahbaz, Emad Sharghi, and two citizens who wish to remain private will soon be reunited with their loved ones - after
enduring years of agony, uncertainty, and suffering," Biden said in a statement released by the White House.

"I am grateful to our partners at home and abroad for their tireless efforts to help us achieve this outcome, including the governments of
Qatar, Oman, Switzerland, and South Korea."

Biden also reminded US citizens about the risk of travelling to Iran and said Washington could not guarantee their freedom should they be detained.

"American passport holders should not travel there," he said.

The White House has come under criticism from Republicans and some Democrats for striking the prisoner exchange deal with Tehran, saying that it could lead to further detentions.

Al Jazeera's Kimberly Halkett says the Biden administration has repeatedly said freeing US citizens imprisoned abroad is a top priority of his presidency.

"Anyone who has a family member in detention would want to see their family member brought home, and that is his top priority. That was the opportunity that was in front of him and so he seized it," Halkett added.

This is a developing story, more to follow.

Five US citizens have been flown out of Iran as part of a widely anticipated prisoner swap deal between Washington and Tehran, a United States official confirmed.

A senior official in US President Joe Biden's administration told reporters on Monday that five freed Americans and two of their US family members were en route to the Qatari capital, Doha.

The White House has named three of the prisoners, who were released to house arrest in advance of the swap, as Siamak Namazi, Emad Sharghi and Morad Tahbaz.

The families of the two others have withheld their identities, but they are said to be a scientist and a businessman. Western media outlets also have reported that one is a woman.

Here's what we know about the Americans being released as part of the deal:

Iran's foreign minister has said his country is ready to implement a Qatar-mediated deal with the United States, under which Washington and Tehran each would free five prisoners and $6bn in Iranian assets held in South Korea would be released.

The broad outlines of the US-Iran deal under which US citizens detained by Iran would be allowed to leave in exchange for the transfer of the funds to banks in Qatar and the release of five Iranians held in the United States were made public on August 10.

Foreign Minister Hossein Amirabdollahian, in a telephone conversation with his Qatari counterpart on Thursday, praised Doha's constructive role during months of negotiations that resulted in clinching the pact, Iranian state media reported.

Qatar's prime minister and foreign minister, Sheikh Mohammed Bin Abdulrahman Al Thani, said the process of wiring the Islamic Republic's unfrozen funds to Qatari banks will be completed as early as next week, Iranian media reported.

Washington has waived sanctions to allow the transfer of $6bn in Iranian funds from South Korea to Qatar, which will monitor how Iran's clerical rulers will spend the funds to purchase humanitarian goods.

In a highly anticipated prisoner exchange, a plane carrying five American prisoners released by Iran has landed in the Qatari capital, Doha. The former detainees, Siamak Namazi, Morad Tahbaz, Emad Sharghi, and two citizens who wish to remain private, disembarked the plane at Doha International Airport, where they were greeted by both US and Qatari officials. Al Jazeera's Imran Khan, reporting from the airport, described a visible sense of relief among the former prisoners and emphasized their imminent return to the US.

 ..... However, the three other released Iranians have decided against returning to Iran. Two have chosen to stay in the US, while one will proceed to a third country. This prisoner exchange was made possible by the agreement between the US and Iran, which also led to the unfreezing of $6 billion in Iranian assets held in South Korea.

 ..... He named the individuals involved and acknowledged the years of agony, uncertainty, and suffering they endured. Biden recognized the tireless efforts of partners both at home and abroad, including the governments of Qatar, Oman, Switzerland, and South Korea.

However, Biden also cautioned US citizens about the risks of traveling to Iran, stating that Washington cannot guarantee their freedom if detained. He advised American passport holders to avoid traveling to the country. The White House has faced criticism from Republicans and some Democrats for the prisoner exchange, with concerns raised about potential repercussions and further detentions.

Responding to the criticism, Al Jazeera's Kimberly Halkett highlighted the Biden administration's repeated emphasis on prioritizing the release of US citizens imprisoned abroad. She noted that anyone with a family member in detention would want them brought home, and that this was Biden's top priority. Halkett explained that the opportunity to secure their release was presented to Biden, and he seized it.

As this is a developing story, further updates are expected to follow.

Washington accused of paying ransom as five detainees from each side are released.

Morad Tahbaz, who holds British, American and Iranian citizenship, was among the prisoners flown out of Iran on Monday afternoon, following weeks of negotiation between Washington and Tehran.

London-born Mr Tahbaz, 67, was arrested in 2018 and sentenced to 10 years in prison on charges of "assembly and collusion against Iran's national security" while working as a climate activist.

His imprisonment has become a major diplomatic dispute between Iran and the UK, and has featured in negotiations between the governments over the detention of Nazanin Zaghari-Ratcliffe.

Roxanne Tahbaz, his daughter, has campaigned in Britain for ministers to do more to secure his release, including at protests outside the Foreign Office.

But Mr Tahbaz was left in Iran when Ms Zaghari-Ratcliffe and another British-Iranian dual national, Anoosheh Ashoori, were released in a deal negotiated by Liz Truss, when she was Foreign Secretary.

Conservationist Morad Tahbaz among prisoners to be swapped in deal involving unfreezing of Iranian oil money. Plus, has the Chinese economy reached its peak?

The US and Iran are expected to pull off a controversial prisoner swap today involving the unfreezing by the Biden administration of $6bn (?4.8bn) of Iranian oil money held in South Korea since 2018.