Families of Americans imprisoned or missing in Iran faulted the U.S. government on Thursday for not doing more to bring their loved ones home and called for establishing a dialogue with Tehran to negotiate their return.

At turns embittered and bewildered, the criticisms of the Obama and Trump administrations were leveled by relatives of three men whom the United States considers hostages of the Iranian government.

The family members attended a hearing before a House foreign affairs subcommittee called on the 12th anniversary of the disappearance of former FBI agent Robert Levinson.

“After three very different presidential administrations, we are no closer to bringing Bob home than when we started,” said Christine Levinson, his wife, who believes her husband is alive and being held in Iran.

“I think it’s necessary for the Trump administration to make it a priority,” she added. “The U.S. government needs to get him home. That’s all we’re asking for.”

Babak Namazi, whose brother Siamak and father Baquer were arrested in Tehran more than three years ago, called on the White House to enter into direct negotiations with Iran to free at least six U.S. citizens or residents known to be imprisoned in Iran.

“The only way is through dialogue,” he said. “We’ve managed to get hostages home from countries that we thought we were going to go to war with imminently. I’m referring to North Korea.”

And Omar Zakka, whose father, Nizar, is a Lebanese citizen but a U.S. permanent resident, said he would be happy just to hear President Trump mention his father’s name and call publicly for his release.

The hearing was held amid growing tensions between Tehran and Washington. During the Obama administration, the plight of Americans imprisoned in Iran was regularly brought up on the sidelines of the lengthy negotiations that led to the 2015 nuclear deal.

Christine Levinson and Babak Namazi struck a bitter tone about the failure of the Obama administration to get their family members home.

“The Obama administration had the opportunity to get Bob home and failed,” said Chistine Levinson. “And they had eight years to do it. I hope that President Trump doesn’t follow that lead, and brings Bob home again.”

Babak Namazi accused the Obama administration of having “abandoned” his brother by not insisting he be part of a prisoner swap coinciding with the Iran nuclear deal.

“It was the Revolutionary Guards who took my family,” he said. “But the Obama administration chose to leave Siamak behind.”

On the day the Iran nuclear agreement was implemented in January 2016, five other Americans imprisoned in Iran were released and all but one, who chose to stay, were flown out of the country as part of a prisoner swap negotiated by Secretary of State John F. Kerry.

Namazi said that he never understood why his brother, who had been arrested four months earlier, was not aboard that flight and that he learned about it from the news media. But he said he learned that the Iranians promised to release Siamak within weeks after it was decided that an American would be left behind “in the name of the greater good of the nuclear deal.”

Their father went to Iran to visit Siamak a few weeks later and was himself arrested. Both men were convicted of collaborating with a hostile foreign power — the United States.

“I spend a lot of time still wondering how our lives would have been so different today had Siamak not been abandoned in January 2016,” Babak Namazi said.

Kerry continued to press for the release of Siamak and Baquer Namazi for a year before the Obama administration ended. In one of his final acts as secretary of state, Kerry called Iranian Foreign Minister Mohammad Javad Zarif to urge that the Namazis be released.

But now, with Trump’s withdrawal from the nuclear agreement and the reimposition of sanctions, tensions have grown more strained. There is no communication between officials from the two countries, and no opportunities even to discuss the fate of U.S. prisoners.

Namazi said his father’s health, at age 82, is deteriorating rapidly. He has been diagnosed with epilepsy, blocked arteries and his knees buckle after only a few steps. He has been released from prison on a medical furlough but not given permission to leave the country.

“The horrific and painful reality is that my father is dying,” he told the committee. “I have begged repeatedly for the Iranian government to allow my sick father to be allowed to leave Iran. We don’t want my father to leave Iran in a coma, or worse, dead.”