A soldier with the New York Army National Guard has died in Ukraine, according to the Guard.

Spc. Joseph Nelk, 21, was deployed to Ukraine to support the 7th Army Training Command’s Joint Multinational Training Group-Ukraine, a news release said. He died on Sunday of apparent natural causes in a non-training-related incident.

Nelk was a cavalry scout assigned to 2nd Battalion, 101st Cavalry Regiment, 27th Infantry Brigade Combat Team. The specialist was one of 220 New York Guard soldiers assigned to the training group, the release said. The group helps train Ukrainian army troops at the Yavoriv Combat Training Center in western Ukraine.

Soldiers from the New York National Guard took over the mission from an Oklahoma National Guard team on Nov. 22, according to the release.

Nelk enlisted in the Guard in March 2015 and completed Advanced Individual Training in January 2016.

His awards and decorations include the National Defense Service Medal and the Army Service Ribbon.

The incident is under investigation.