The US State Department has denied reports on Iranian television that it has reached a deal that would see the release of detained American citizens.
State reporters announced on Sunday that Iran planned to release prisoners with ties to Western countries in a deal it had struck with the US and the UK.
According to the report, the US and the UK would participate in a prisoner swap with Iran and then unfreeze $7bn that had been frozen by sanctions placed on the country.
"The Americans accepted to pay $7bn and swap four Iranians who were active in bypassing sanctions for four American spies who have served part of their sentences," the reporter said.
However, the US has denied any involvement in those negotiations, and the UK has played down the reports.
According to the Associated Press, US State Department spokesman Ned Price immediately denied the report.
"Reports that a prisoner swap deal has been reached are not true," Mr Price said. "As we have said, we always raise the cases of Americans detained or missing in Iran. We will not stop until we are able to reunite them with their families."
The four Americans imprisoned in Iran are Baquer and Siamak Namazi, Morad Tahbaz and Emad Shargi.
The Namazis are a father and son duo held by the country. Siamak, the son, was arrested in 2015 while working as the head of strategic planning at a Dubai-based petroleum company. His father war arrested a year later after he was granted permission to visit his son in prison.
Mr Tahbaz – who also holds British citizenship – was arrested while using cameras to track the movements of endangered species while working for the Persian Wildlife Heritage Foundation. He was charged with espionage, and denies having any involvement in spying activities.
Mr Shargi, a businessman, was arrested in 2018 and sentenced to 10 years in prison for alleged actions against the country. The US State Department has maintained that Mr Shargi is being wrongfully detained.
It was not immediately clear from the state broadcast which of Iran's prisoners would have been part of the alleged trade.
The Iranian report also claimed that the UK would pay Iran £400m for the release of Nazanin Zaghari-Ratcliffe, a British-Iranian woman who was sentenced to another year in prison by the country for spreading "propaganda against the system" by participating in a protest in front of the Iranian Embassy in London in 2009.
Her latest year of prison was tacked on after she completed a five-year sentence for allegedly plotting to overthrow the country's government. She denies any involvement in revolutionary plots.
A spokesperson for Britain’s Foreign Office could not confirm the report and said: “We continue to explore options to resolve this 40-year-old case and will not comment further as legal discussions are ongoing.”
Ms Zaghari-Ratcliffe's husband, Richard Ratcliffe, said he had not been informed of any negotiations involving his wife.
"We haven't hear anything," he said. "Of course, we probably wouldn't, but my instinct is to be skeptical at present."