WASHINGTON — Lawmakers are calling on Trump administration officials to explain why they have refused so far to grant a visa to an Afghan interpreter who they say has faced death threats and an assassination attempt from the Taliban.

Muhammad Kamran and his family fled to Pakistan from Afghanistan due to Taliban threats, according to his lawyer and members of Congress. Kamran has been trying to get a U.S. visa for four years, but U.S. authorities have turned down his previous applications to resettle in the United States, citing unspecified "security concerns." Kamran is one of thousands of Afghan translators who have struggled to get U.S. visas despite working alongside U.S. troops and drawing the ire of jihadis.

After congressional inquiries last year, the administration recently reopened Kamran's case, conducting an interview on April 2 with the former interpreter, according to lawmakers.

In a bipartisan letter last week to the U.S. Citizenship and Immigration Services (USCIS), four members of Congress asked officials to provide more information about the status of Kamran's case.

"It has been nearly two months since the interview. We have not been made aware of any further contact between U.S. officials or the Kamran family," said the letter from Democratic Reps. Jamie Raskin, Pramila Jayapal and John Garamendi, and Republican Rep. Tom Reed.

The Department of Homeland Security also has failed to provide Congress with a briefing on the case despite a promise from former Secretary of Homeland Security Kirstjen Nielsen at a congressional hearing in December 2018, the letter stated.

Although security concerns have to be taken into account, the lawmakers wrote, "We remain concerned as how the process will proceed, as it took more than eight months simply to respond to our initial inquiry."

In the meantime, Kamran and his family "are facing dire circumstances in the form of extortion, beatings and assaults by the Pakistani police and military, as well as the constant threat of deportation to Afghanistan where they would face near certain death," according to the letter, obtained by NBC News.

"We simply cannot hang these people out to dry like this."

The USCIS declined to comment on the case, citing "privacy concerns." The embassy of Pakistan was not immediately available for comment.

While U.S. authorities have so far declined to grant the 35-year-old Kamran a visa, one of his brothers — who also worked as an interpreter for the U.S. military — has been living in the United States for years, as has his sister, according to Kristy Perano, an American graduate student who has championed Kamran's case. Kamran first applied for a U.S. visa in 2014.

After failing to secure status as a refugee, Kamran applied for a humanitarian exception, known as "humanitarian parole," in 2017 to allow him to stay temporarily in the United States. He also applied separately for his wife and children, but U.S. authorities denied the requests, even for his youngest daughter, who was 4 years old at the time, according to his lawyer, Danielle Rosche.

In denying Kamran’s applications, U.S. authorities did not cite more specific immigration laws that require evidence of support for terrorism or affiliation with terrorist groups, Rosche said.

"For these reasons, we believe that there is in fact no evidence supporting USCIS’s accusation that he and his family are a security threat," she said.

More than 30 lawmakers expressed concern about Kamran's case in a letter to DHS in July 2018.

"They've not given us information that would remotely justify this treatment of his family," Rep. Raskin, who has raised Kamran's case at congressional hearings, told NBC News.

Raskin, a Democrat from Maryland, said Kamran's case is part of a much wider problem involving thousands of interpreters who served alongside Americans in Afghanistan and Iraq who are struggling to secure visas to the United States.

"I think it's a scandalous situation. These people were brothers and sisters in arms and now we're treating them as strangers at best or as dangerous suspects. It's a slap in the face to these people," Raskin said.

"It obviously makes us seem like an unreliable ally. We simply cannot hang these people out to dry like this."

Due to their association with U.S. troops and aid officials, the former interpreters have come under attack and endured death threats. The U.S. government set up special visa programs more than 10 years ago to allow interpreters to resettle in the United States, but the visa process has been plagued by delays and come under criticism from Congress and veterans groups.

The issue has taken on a new urgency with President Donald Trump weighing plans to possibly pull U.S. troops out of Afghanistan.