Iran and the United States will exchange prisoners on Monday after some $6 billion once frozen in South Korea reached Qatar, a key element of the planned swap, officials said.

The planned exchange comes just ahead of the United Nations General Assembly in New York, where Iran’s hard-line President Ebrahim Raisi will speak.

However, the swap won’t mean that tensions have been lowered between the US and Iran, which now enriches uranium closer than ever to weapons-grade levels.

Iranian Foreign Ministry spokesman Nasser Kanaani was the first to acknowledge the swap would take place Monday. He said the cash sought for the exchange was now in Qatar.

An individual with direct knowledge of the deal, who spoke to The Associated Press on condition of anonymity given the exchange had yet to be concluded, later said that both Iranian and US officials had been notified by Qatar that the money had been transferred from Switzerland into the Gulf Arab nation.

Kanaani made his comments during a news conference aired on state television, but the feed cut immediately after his remarks without explanation.

“We witnessed freezing of parts Iranian assets in some countries including South Korea,” Kanaani said.

“As part of our policy of active foreign diplomacy, fortunately, Iran’s frozen assets in South Korea were released and God willing today the assets will start to be fully controlled by the government and the nation.”

“On the subject of the prisoner swap, it will happen today, and five prisoners, citizens of the Islamic Republic, will be released from the prisons in the US,” Kanaani added.

“Five imprisoned citizens who were in Iran will be given to the US side reciprocally, based on their will. We expect these two issues fully take place based on the agreement.”

He said two of the Iranian prisoners will stay in the US.

Iranian news agencies immediately afterward reported, quoting Kanaani, that the prisoner swap would be done on Monday. There was no other information immediately released by the agencies and Washington did not acknowledge the comments.

However, a Qatar Airways Airbus A320 landed on Monday morning at Mehrabad International Airport in Tehran, where previous prisoner releases have taken place, according to flight-tracking data analyzed by the AP. Qatar Airways uses Tehran’s Imam Khomeini International Airport for its commercial flights.

Iranian news agencies immediately afterward reported, quoting Kanaani, that the prisoner swap would be done on Monday. There was no other information immediately released by the agencies and Washington did not acknowledge the comments.

The announcement by Kanaani comes weeks after Iran said that five Iranian-Americans are now under house arrest as part of a confidence-building move while Seoul allowed the frozen assets, held in South Korean won, to be converted into euros.

That money was then sent to Qatar, an interlocutor between Tehran and Washington in the negotiations.

The planned swap has unfolded amid a major American military buildup in the Persian Gulf, with the possibility of US troops boarding and guarding commercial ships in the Strait of Hormuz, through which 20% of all oil shipments pass.

The deal has also already opened President Joe Biden to fresh criticism from Republicans and others who say that the administration is helping boost the Iranian economy at a time when Iran poses a growing threat to US troops and Mideast allies. That could carry over into his reelection campaign as well.

On the US side, Washington has said the planned swap includes Siamak Namazi, who was detained in 2015 and was later sentenced to 10 years in prison on internationally criticized spying charges; Emad Sharghi, a venture capitalist sentenced to 10 years; and Morad Tahbaz, a British-American conservationist of Iranian descent who was arrested in 2018 and also received a 10-year sentence.

US officials have so far declined to identify the fourth and fifth prisoners.

The five prisoners Iran has said it seeks are mostly held over allegedly trying to export material to Iran.