Washington ? Stressed by war and long overseas tours, U.S. soldiers killed themselves last year at the highest rate on record, the toll rising for a fourth straight year and even surpassing the suicide rate among comparable civilians.

Army leaders said they were doing everything they could think of to curb the deaths and appealed for more mental health professionals to join and help out.

At least 128 soldiers committed suicide in 2008, the Army said Thursday. And the final count is likely to be even higher because 15 more suspicious deaths are still being investigated.

“Why do the numbers keep going up? We cannot tell you,” said Army Secretary Pete Geren. “We can tell you that across the Army we’re committed to doing everything we can to address the problem.”

It’s all about pressure and the military approach, said Kim Ruocco, 45, whose Marine husband was an officer and Cobra helicopter pilot who hanged himself in a California hotel room in 2005. That was one month before he was to return to Iraq a second time.

She said her husband, John, had completed 75 missions in Iraq and was struggling with anxiety and depression but felt he’d be letting others down if he sought help and couldn’t return.

“He could be any Marine because he was highly decorated, stable, the guy everyone went to for help,” Ruocco said in a telephone interview. “But the thing is … the culture of the military is to be strong no matter what and not show any weakness.”

Ruocco, of Newbury, Mass., was recently hired to be suicide support coordinator for the nonprofit Tragedy Assistance Program for Survivors. She said she feels that the military has finally started to reach out to suicide survivors and seek solutions.

“Things move slowly, but I think they’re really trying,” Ruocco said.

At the Pentagon on Thursday, Col. Elspeth Ritchie, a psychiatric consultant to the Army surgeon general, made a plea for more professionals to sign on to work for the military.

“We are hiring and we need your help,” she said.

Military leaders promised fresh prevention efforts will start next week.

The new suicide figure compares with 115 in 2007 and 102 in 2006 and is the highest since current record-keeping began in 1980. Officials expect the deaths to amount to a rate of 20.2 per 100,000 soldiers, which is higher than the civilian rate — when adjusted to reflect the Army’s younger and male-heavy demographics — for the first time in the same period of record-keeping.

Officials have said that troops are under unprecedented stress because of repeated and long tours of duty due to the simultaneous wars in Iraq and Afghanistan.

Yearly increases in suicides have been recorded since 2004, when there were 64 — only about half the number now.