Relatives of five U.S. citizens who formerly led the oil company Citgo are asking President Trump for help to free the men as they end a second year living in the windowless basement of a military intelligence facility in Venezuela.

The businessmen are nearly unrecognizable from weight loss. One was too weak to lift his less than four-foot son during a recent visit. And after waiting 18 months for a preliminary hearing, they still have no trial date on vague corruption charges.

The five Americans, all dual citizens, were arrested a week before Thanksgiving 2017, accused of negotiating a loan on poor terms. Supporters saw it as pretext for socialist President Nicolas Maduro to pack the Venezuela-owned but U.S.- headquartered company with loyalists.

Then-Citgo CEO Jose Angel Pereira, the only non-U.S. citizen detained with the group, was replaced by Asdrubal Chavez, a cousin of Maduro's mentor Hugo Chavez. Asdrubal Chavez left this year when the Venezuelan opposition took control of the company.

Families are seeking Trump’s intervention after a strategy of silence to avoid antagonizing authorities failed.

“He's the president of the United States. I feel like if he really wanted, he could bargain their release … the issue is getting it to his attention,” said Gustavo Cardenas Jr., whose father Gustavo Cardenas, 53, was Citgo’s head of public affairs. "It's super easy for the Venezuelan government to keep it going. There is no pressure to release them and no pressure to sentence them."

“I don’t know if [Trump] knows about our case," said Veronica Vadell Weggeman, whose father Tomeu Vadell, 60, was Citgo’s vice president for refining.

"He has been so great at bringing hostages home from other places, and we hope he is working diligently on this," Vadell Weggeman said.

Cristina Vadell, who is organizing efforts to advocate for her father and the others, said, "We believe Trump could resolve it, of course, but we need all the stakeholders to agree ... Maduro and others in Venezuela are really the ones who are holding the keys."

Tomeu Vadell, Citgo’s former vice president for refining, is pictured before and after his detention in Venezuela. (Courtesy of Vadell family)

Relations between the U.S. and Venezuela declined over the two years, as the U.S. recognized parliament leader Juan Guaido, who opposes Maduro as interim president of the country, effectively ending Maduro's control of Citgo.

The American detainees also include former vice president for supply Jorge Toledo, former vice president for shared services Jose Luis Zambrano, and former Corpus Christi refinery director Alirio Zambrano.

All of the detainees have been held in the same facility, bringing a sense of camaraderie despite stretches of up to months without sunlight and meals that feature a bowl of plain rice or pasta.

"It helps not being alone in the situation," said Gustavo Cardenas Jr. "They pray, they walk together."

Over time, Venezuelan authorities have softened some policies, allowing families to bring outside food once a week during visitations. And the recent change of leadership at Citgo opens the door to possible additional support for the families.

The men's families lost their salaries in May 2018 when they were cut off by company leaders. But the company allowed continued health insurance, which helps one of the families with a son who has a long-term illness that requires surgery.

Gustavo Cardenas, Citgo’s former head of public affairs, is pictured before and after he was detained. (Courtesy of Cardenas family)

Trump's intervention has coaxed hostage releases in various countries, including Venezuela, where Maduro freed former Mormon missionary Joshua Holt, who faced weapon charges, in May 2018 amid pressure from both Trump and Utah leaders.

Rep. Pete Olson, a Houston Republican, is the lawmaker most involved in the case. He told the Washington Examiner, "The release of the Citgo Six will require advocacy by every level of government, including President Trump and his State Department."

Olson said he's glad to hear the men's conditions improved, but he hopes that more attention will end the detention and that Citgo will do more for the families in the meantime.

"The Citgo Six were imprisoned while visiting Venezuela on official Citgo business," Olson said. "Releasing the Citgo Six is the priority, and Citgo — which is owned by the Venezuelan government but works in our backyard here in Houston — has the power to support their families in the United States as we work toward that goal."

Tomeau Vadell is flanked by his daughters Cristina (left) and daughter Veronica (right) on Thanksgiving 2015. His wife Dennysse, son Diego, and son-in-law also are pictured. (Courtesy of Vadell family)

In a statement, Citgo said: "We pray for the safety of our employees, and for their families. As a company, Citgo believes all human rights must be respected. We have met with and continue to provide support to each of the families of those who are detained by Maduro’s regime, including legal expenses, health care coverage and other benefits. Citgo also continues to support the U.S. Government’s efforts to secure their release."

The U.S. Justice Department has pursued corruption at Citgo from the time the men led the company, though none of the detainees have been named in court documents. One man pleaded guilty last year to bribing some company leaders, but the case appears unrelated to the Venezuela detentions.

A White House spokesman did not respond to a request for comment.

"Sometimes it does feel hopeless because we can't believe we've reached the two-year mark," said Vadell Weggeman. Her sister Cristina Vadell said, "We try to stay very positive ... he's been so positive and strong in his faith that he's going to see his family again."