The US Air Force says 137 personnel across the active duty, National Guard and Reserve died by suicide in 2019, a 33 percent increase over the previous year.

Suicide is a difficult national problem without easily identifiable solutions that has the full attention of leadership, Lieutenant General Brian Kelly, deputy chief of staff for manpower, personnel and services for the Air Force, told Military.com.

The new total marks the highest annual number since the Air Force began keeping an official record in 2008, said service spokeswoman Lynn Kirby.

Some 60 active-duty airmen died by suicide in 2018 and the service lost 103 airmen across the total force that year, according to the US Department of Defense.

Our teammates are taking their own lives, Chief Master Sergeant of the Air Force Kaleth Wright announced. We lose more airmen to suicide than any other single enemy.

Speaking to Military.com in October, the chief said that, over the course of his career, he has heard feedback from airmen who felt the most hopeless during deployments, unable to connect with someone from their unit or loved ones back home.

Officials raised concerns over rising suicide levels in the Air Force in August last year.

Men are statistically more likely to die by suicide than women, according to the American Foundation for Suicide Prevention. Men make up around 80 percent of the active-duty Air Force.

The rate of suicide among active duty troops has increased significantly over the past five years, according to a Pentagon report released in September.

US Defense Secretary Mark Esper said in September that the military was caught up in what some call a national epidemic of suicide among our youth.