ABC News November 20, 2019

2 US service members killed in helicopter crash in Afghanistan

WATCH: 2 US service members killed in helicopter crash in Afghanistan

Two U.S. service members were killed in a helicopter crash in Afghanistan on Wednesday. U.S. military officials said it did not appear that the helicopter went down as a result of enemy fire.

"Two U.S. service members were killed in a helicopter crash on November 20, 2019 in Afghanistan," said a statement issued by U.S. Forces Afghanistan.

"The cause of the crash is under investigation, however preliminary reports do not indicate it was caused by enemy fire," said the statement.

(MORE: US and Australian hostages held by Taliban for over 3 years released in prisoner swap)

No other details were provided by U.S. military officials about the circumstances of the deadly crash or where in Afghanistan it took place.

The two deaths bring to 19 the number of U.S. combat deaths in Afghanistan this year -- the deadliest year for U.S. forces there in five years.

The U.S. military statement said that in accordance with Defense Department policy the names of the service members would not be disclosed until 24 hours after their next of kin have been notified.

Thomas Watkins/AFP/Getty Images
In this photo taken on June 6, 2019, US soldiers look out over hillsides during a visit of the commander of US and NATO forces in Afghanistan General Scott Miller at the Afghan National Army (ANA) checkpoint in Nerkh district of Wardak province.

There are still 13,000 U.S. troops in Afghanistan, most of them involved in a mission to train, advise and assist Afghan security forces in their fight against the Taliban and the ISIS affiliate in Afghanistan.

Peace talks between the United States and the Taliban stalled in early September after the U.S. ended discussions following the death of an American soldier in a bombing in Kabul.

(MORE: 18-year-old US soldier to serve in Afghanistan 18 years after conflict began)

By that point the talks had reached a tentative agreement that could have led to the withdrawal of as many as 5,000 American troops from Afghanistan.

The Trump administration has advocated for the withdrawal of all U.S. forces from Afghanistan, but that move could only happen if talks restart and the Afghan government is brought into the peace talks.

On Tuesday, two western hostages held by the Taliban for more than three years were freed in exchange for the transfer to Qatar of three senior Taliban leaders held by the Afghan government.

(MORE: US has quietly reduced troops in Afghanistan by 2,000)

The release of American Kevin King and Australian Timothy Weeks appears to have been intended to jumpstart the stalled peace talks.

"It is a good step, but it’s only that," Secretary of State Mike Pompeo said of the exchange as he traveled to Brussels.

"But it’s good. I think they’ll build confidence, there are a handful more that we hope will happen in the next few days, some Afghan prisoners who we hope will be released, a handful things after that," Pompeo said.

"We hope they’ll begin to build a foundation that we can get comfortable that a peace and reconciliation process has an opportunity of being successful," he added. "We’ve been working hard at it, we’re still working hard at it."

ABC News' Conor Finnegan contributed to this report.