Washington Post reporter Jason Rezaian has been imprisoned in Iran for more than 300 days. The House Foreign Affairs Committee heard testimony on June 2, 2015, from his brother, Ali, who spoke about Jason and the family’s plea to bring him home. (AP)

The House Foreign Affairs Committee on Tuesday called on Iran to release three Americans imprisoned there, including a Washington Post reporter, and provide information on a fourth who is missing.

After hearing from relatives frustrated that the fate of the four is not a central part of nuclear negotiations with Iran, most committee members said they would not support an agreement without freedom for the jailed Americans.

“Congress should get real serious,” said Rep. Randy Weber (R-Tex.). “No agreement, period, until Iran releases the hostages. I hope John Kerry, President Obama, everybody on their team comes to their senses and says if human rights is not the main thing with this regime, how can you trust them with anything else?”

The hearing comes at a critical time in the Iran nuclear talks. Negotiators for Iran and six world powers, led by the United States, are racing to make a deal before a temporary accord expires June 30.

The deadline hung over the testimony as the relatives said they feared pressure on Iran could slip away once the talks conclude.

Ali Rezaian, brother of Washington Post reporter Jason Rezaian, talks to a reporter during a television interview at the National Press Club in Washington on May 26, 2015. (Carlos Barria/Reuters)

“We do worry that regardless of the outcome of the deal, [there] won’t be a sense of urgency to get any of our family members home anymore,” said Daniel Levinson, the son of Robert Levinson, a former FBI agent who disappeared in Iran in 2007 while working as a contract employee for the CIA.

Naghmeh Abedini, whose husband, Saeed Abedini, was sentenced to eight years in prison for conducting Bible-study gatherings, said June is a critical month for her husband’s fate.

“If we don’t get the Americans out, I don’t know when we will have more leverage,” she said. “This is a very crucial time.”

Some committee members said Iran was showing contempt for the United States by putting Post reporter Jason Rezaian on trial last month. The Post’s Tehran bureau chief was arrested more than 10 months ago, and his trial started May 26, then was abruptly adjourned.

His older brother, Ali Rezaian, said the court-appointed lawyer has been informed that the trial on espionage and other charges will resume Monday.

Committee members said the timing of Rezaian’s trial was no coincidence.

“We hope at this crucial junction, with less than a month to go before an agreement with Iran, this is the time to bring forward the cases,” said Rep. Eliot L. Engel of New York, the senior Democrat on the committee. “That they dare to put someone on a show trial, it just infuriates me.”

Ali Rezaian praised the committee for highlighting the plight of the four Americans.

“Let me be very clear,” he said. “The charges against Jason are false. Jason did sometimes write about Iran’s domestic and foreign policy, but this is perfectly legal conduct and recognized the world over as practicing journalism.”

Some of the family members laid out the mathematics of their predicament. Ali Rezaian noted that his brother had been in prison for 315 days. Daniel Levinson said 3,007 days had passed since his father’s disappearance. Sarah Hekmati said the trial of her brother, Amir Hekmati, on an accusation of spying lasted 15 minutes before he was given a death sentence, which was commuted on appeal to 10 years.

Unlike some of the relatives testifying beside her, Sarah Hekmati had not waged an ambitious public campaign drawing attention to her brother’s almost four years in prison.

She said Iranian and U.S. officials initially advised her family not to publicly discuss her brother, a former Marine arrested four years ago on his first visit to the country where his parents were born. Officials in both countries told the Hekmatis that talking to the news media would politicize Amir’s case and place him in danger, Hekmati said.

“Our family has learned that our silence allowed him to suffer the worst torture imaginable,” she said.

The State Department has raised the plight of the Americans at virtually every round of talks, but always on the sidelines, not in the formal negotiations. State Department officials have said the talks about curbing Iran’s nuclear program in exchange for easing sanctions are for the global good, and they have resisted calls in Congress to make the prisoners’ release a precondition for a deal.

Several members of the committee, and some of the family members, criticized that strategy.

“Why we’re here now is not about centrifuges, PMD or snapbacks,” said Rep. Theodore E. Deutch (D-Fla.), citing some of the technical terms involving nuclear weapons and sanctions. “It’s about respect for human rights, it’s about dignity, and it’s about justice.”

Asked what she would say to Iranian officials, Abedini said: “No more discussions till you first release the Americans. Then we’ll talk further.”

The language used to describe Iran was frequently harsh.

Rep. Mark Meadows (R-N.C.) likened Iranian diplomats to the students who held American diplomats hostage during the 444-day occupation of the U.S. Embassy in Tehran that ended in early 1981.

“The only difference is today the terrorists and thugs wear suits and give the illusion of being international diplomats,” he said.