Tehran and Washington are inching closer to an agreement on the release of Americans imprisoned in Iran.

The revelations were made by Oman’s foreign minister, Sayyid Badr Albusaidi, speaking to Al-Monitor who claimed on Wednesday that he feels a sense of “seriousness” on the part of both the US and Iran.

He said negotiators are doing their best to salvage the 2015 nuclear pact under which the Islamic Republic agreed to curb its nuclear ambitions in exchange for sanctions easing.

Siamak Namazi, Emad Shargi and Morad Tahbaz are three of an unknown number of dual nationals imprisoned in Tehran’s notorious Evin Prison on espionage charges.

Al-Monitor also quoted experts as saying that the Biden administration will not reach a deal with Iran over its nuclear dossier unless Tehran releases the prisoners first.

If inked, the deal would lead to release of billions of Iran’s frozen assets in North Korea though according to sanctions, the Iranian regime would only be allowed to use those funds for humanitarian issues.

Oman, Qatar, and the UK have also been attempting to mediate to bring the nuclear talks to a conclusion, but attempts have failed so far. “I can say they are close. This is probably a question of technicalities,“ Albusaidi told Al-monitor.

Albusaidi did not confirm Oman's involvement, but said his country has “offered in good faith our offices to help both sides, be it here or anywhere else.”

Oman has been active in mediation efforts between Iran and its neighbors, including the recent detente between Saudi Arabia and Iran, of which Oman, China and Iraq played key roles.