Iranian American businessman Siamak Namazi is pictured in San Francisco in 2006. (Courtesy of Ahmad Kiarostami/Via Reuters)

Few people have watched the deteriorating relations between Iran and the United States with as much concern as Babak Namazi.

The stakes are intensely personal. His elderly father and his younger brother, both U.S. citizens, are imprisoned in Iran after being convicted of espionage and collaborating with the U.S. government. They had an appeals hearing Wednesday, but there is little hope the verdict will be overturned.

The Obama administration had pushed Iran to free Siamak and Baquer Namazi, and other Americans detained or missing in Iran, until talks collapsed in President Barack Obama’s final days in office. Since then, there has been no contact between Washington and Tehran, according to the Iranian Foreign Ministry.

So Babak Namazi came to Washington this week to urge the Trump administration to restart efforts to gain his family members’ freedom after more than a year in custody.

“I was hopeful it would have been resolved ages ago,” said ­Namazi in an interview before he met Tuesday with a senior official from the National Security Council. “With a new administration in place, we hope it draws the attention we need. My father is running out of time. When he talks to my mom, he complains that he’s dizzy. And he says something he’s never said before: ‘Pray for me.’ ”

When President Trump took office, he inherited responsibility for the fates of Americans taken hostage or held for questionable reasons in foreign prisons.

At least six Americans are in the hands of militants, including a Pennsylvania woman, her Canadian husband and their two children born in captivity after their kidnapping near the Afghanistan-
Pakistan border. At least four U.S. citizens with dual nationality and two green-card holders are behind bars in Iran, and a former FBI agent who disappeared there a decade ago may still be alive.

The total number of American hostages is a tightly guarded secret. In 2015, when U.S. hostage policy changed to not seek prosecution of Americans who negotiate ransoms for loved ones held abroad, Obama put the number at more than 30.

Efforts to bring hostages home continue through the work of career employees in the FBI’s Hostage Recovery Fusion Cell and the office of the Presidential Envoy for Hostage Affairs in the State Department, both of which were created in 2015.

“The communication with us is as strong as it has been,” said Debra Tice, who recently spoke with homeland security adviser Thomas Bossert about her son. Austin Tice was kidnapped while reporting in Syria in 2012 and is believed to be alive. “A lot of our team remains and was unaffected by the [presidential] transition.”

The change in administrations has created two voids, however. When he was secretary of state, John F. Kerry pushed for prisoner releases during his regular conversations with Iranian Foreign Minister Mohammad Javad Zarif to discuss the Iran nuclear deal. No one from the Trump administration has the same relationship.

And the hostage envoy position has not been filled since James O’Brien resigned on Jan. 20. A deputy is filling in, and it is not clear whether the job will be filled or have the same mandate to find new approaches to negotiations.

“My thesis in the job was that getting Americans home is right and shows that our government is effective, because it changes the behavior of people on the other side even before other, difficult parts of our relationship are addressed,” O’Brien said. “I hope that’s the same approach that the administration is using now.”

The White House insists it is fully engaged in the effort, even with Tehran.

“The Trump administration is truly, unwaveringly committed to the return of all U.S. citizens held in captivity in Iran, or anywhere in world,” said an official with the National Security Council, speaking on the condition of anonymity under ground rules set by the White House. “Specifically, the Iranian cases continue to be a high priority for the U.S. ­government.”

The Americans imprisoned in Iran have all been accused of spying for the United States. It is widely believed that the charges are baseless and that the prisoners are pawns for the Islamic Revolutionary Guard Corps.

Recently, the deputy head of the Corps bragged that the United States had paid ransom to free Washington Post reporter Jason Rezaian a year ago, a payment U.S. officials insisted was an out-of-court settlement of an old lawsuit. But the boast suggests the powerful group is angling for a deal.

“What the Revolutionary Guards have done to Siamak and others has reached a point of diminishing returns,” said Reza Marashi of the National Iranian American Council. “Before, their strategy was to prevent further progress in U.S.-Iran relations. Nobody argues Trump is trying to improve on Obama’s progress. So the prisoners have become a liability. The Revolutionary Guards have backed themselves into a corner, and they are looking for a face-saving way out.”

For the families, a way out cannot come soon enough.

Fatemeh Shahini, a San Diego woman whose brother, Robin, was convicted of espionage last year, said he is on a hunger strike that has caused him to lose 40 pounds and be beaten by prison guards.

Babak Namazi worries about the health of his 80-year-old father, Baquer, who has had triple bypass heart surgery. He was recently hospitalized in Iran, suggesting his captors do not want him to die on their watch.

Siamak is under relentless pressure,” Babak Namazi said of his brother. “Interrogations have continued, even after his conviction, to the point he is despondent and has no hope.”

His attorney, Jared Genser, of Freedom Now, said a senior Iranian official vowed to Kerry that the Namazis would be released “soon” after Rezaian and four other U.S. citizens were freed in January 2016.

“High-level discussions between both sides included detailed requests of what each might need,” Genser said. “But ultimately, the differences from the Iranian side far exceeded what the U.S. government would ever be capable of delivering.”

Now, their hopes lie in Trump, despite his sometimes bellicose attitude toward Iran and the nuclear deal. They quoted a Trump tweet two weeks before the election, in reaction to the Namazis being sentenced: “This doesn’t happen if I’m president.”