The death of the two service members on Wednesday comes as America's chief negotiator with the Taliban resumed talks with representatives of the terrorist group in Qatar on Tuesday, hoping to finalize agreements with the Taliban and the Afghan government.
USA envoy Zalmay Khalilzad sought to bolster optimism for a peace agreement last week when he said in a tweet that he hoped this is the final year that the country is at war.
Baradar is one of the Taliban's founders and has perhaps the strongest influence on the insurgent group's rank-and-file members.
This week, Trump said it was "ridiculous" that USA troops have been in the country for nearly 18 years. Some U.S. forces carry out counter-terrorism operations.
Two United States military personnel have been "killed in action" in Afghanistan, NATO announced, without saying how the pair died.
More than 2,400 American troops have been killed in Afghanistan since the US-led invasion in 2001 to topple the Taliban, whose government had harbored al-Qaida leader Osama bin Laden.
Zalmay Khalilzad, an Afghan-born US diplomat who has been leading the negotiations with the Taliban since previous year is scheduled to travel to Kabul after his talks with the Taliban officials.
The Taliban now control more territory than at any point since the United States bombed them out of power in 2001 for sheltering al Qaeda, the group blamed for the September 11 attacks on the United States.
The United States formally ended its Afghan combat mission in 2014 but about 14,000 USA troops remain in the country, mainly training and advising government forces battling the Taliban, an affiliate of the Islamic State group, and other militants.