Jason Rezaian, The Washington Post’s reporter in Tehran, has been detained since July. (Zoeann Murphy/The Washington Post)

The framework agreement on Iran’s nuclear program unveiled Thursday provided little hint about how a deal may affect the fate of four Americans detained or missing there.

The Obama administration has made the release of the Americans, who include Washington Post correspondent Jason Rezaian, another priority in its ties with Iran.

In addition to Rezaian, who has been the newspaper’s correspondent in Tehran since 2012 and holds dual U.S. and Iranian citizenship, the Americans include Amir Hekmati, a former U.S. Marine detained since 2011, and Saeed Abedini, a Christian pastor.

Robert Levinson, a retired FBI agent who also had worked for the CIA, disappeared during a visit to Iran’s Kish Island more than eight years ago. While Iran has denied holding him, U.S. officials believe he has been in Iranian custody.

Secretary of State John F. Kerry, speaking to reporters in Switzerland after negotiators announced the agreement on Thursday, said that U.S. officials had raised the fate of the Americans in every meeting with their Iranian counterparts.

Negotiators from Iran and major world powers reached agreement on a framework for a final agreement to curb Tehran’s nuclear program in exchange for relief from international sanctions, participants in the talks said. (Yahoo News)

Asked whether the detainees would be released as a goodwill measure if a final deal can be achieved, Kerry declined to provide details but said officials remain focused on the issue.

“We have a very specific process in place to try to deal with it,” he said. “We call on Iran again today, now, in light of this, to release these Americans and let them get home with their families.”

Iranian security forces picked up Rezaian and his wife, Yeganeh Salehi, last July. Although Salehi was released after two months, Rezaian, 39, remains held at the notorious Evin prison in Tehran. During his 254-day captivity, he has not met with an attorney, and the government has not announced charges against him, his family said.

“Now that the framework agreement is in place, we call on the Iranian leadership to review the evidence their underlings claim to have against Jason,” Rezaian’s brother, Ali, said in a statement. “If they do, we are certain they will see that Jason has done no harm to Iran. Otherwise, they should ensure the judiciary stop their inhumane delays, make public their case against Jason and let the World see why they have stolen 8 months of Jason’s life.”

Martin Baron, executive editor of The Washington Post, said Iran’s handling of the case amounted to “state-sponsored injustice.”

“Iran should have ended this cruel and unconscionable charade months ago, and with the talks now adjourned, there can be no excuse for further delay,” Baron said in a statement.

Highlights of the Iran deal

“It is long past time for Iran’s leaders to demonstrate fairness and a commitment to abide by Iran’s own rules, which could only result in Jason’s immediate release.”

Karim Sadjadpour, an Iran scholar at the Carnegie Endowment for International Peace, said that hardliners in Iran had used American hostages or prisoners, starting with the 1979 U.S. Embassy seizure, to exercise their influence and undermine those who favored greater engagement.

If a nuclear deal is struck, “I think the likelihood of their release goes up, but it’s difficult to predict and each of their circumstances are different,” Sadjadpour said.

Sadjadpour said that Levinson’s links to the CIA would likely make his release the most complicated. U.S. officials have been uncertain whether Levinson, who was reportedly in poor health, remains alive.

Carol Morello in Lausanne, Switzerland, contributed to this report.