Suicides in the US Army will hit a new high this year, a top general said in a disclosure likely to increase concerns about stress on US forces ahead of an expected buildup in Afghanistan.

The findings, released as President Barack Obama inches toward a decision to send up to 40,000 additional troops to Afghanistan, show the number of active-duty suicides so far in 2009 has already matched last year's record of 140 deaths.

"We are almost certainly going to end the year higher than last year," General Peter Chiarelli, the Army's vice chief of staff, told a Pentagon briefing.

"This is horrible, and I do not want to downplay the significance of these numbers in any way."

Another 71 soldiers committed suicide after being taken off active duty in 2009 -- nearly 25 percent more than the end-year total for 2008. Some had returned home only weeks before taking their own lives.

The figures applied only to the US Army. Data from other branches of the armed services was not immediately available.

Chiarelli cautioned against generalizing about the causes of the suicides, or assuming links to combat stress on forces stretched thin by the wars in Iraq and Afghanistan.

He said the causes were still unclear and noted that roughly a third of the soldiers who took their own lives had never been deployed abroad.

The Army recently revealed that about one in five lower rank soldiers suffered mental health problems like depression.

The latest data and this month's shooting spree at a base in Fort Hood, Texas attributed to an Army psychiatrist have raised new questions about the effects of combat stress and the state of the military's mental health system.