TAMPA, Florida (Reuters) - Suicides among U.S. special operations forces, including elite Navy SEALs and Army Rangers, are at record levels, a U.S. military official said on Thursday, citing the effects of more than a decade of "hard combat."

The number of special operations forces committing suicide has held at record highs for the past two years, said Admiral William McRaven, who leads the Special Operations Command.

"And this year, I am afraid, we are on path to break that," he told a conference in Tampa. "My soldiers have been fighting now for 12, 13 years in hard combat. Hard combat. And anybody that has spent any time in this war has been changed by it. It's that simple."

It may take a year or more, he said, to assess the effects of sustained combat on special operations units, whose missions range from strikes on militants such as the 2011 SEAL raid that killed al Qaeda chief Osama bin Laden to assisting in humanitarian disasters.

He did not provide data on the suicide rate, which the U.S. military has been battling to lower. In 2012, for example, more active duty servicemen and servicewomen across the U.S. armed forces died by suicide - an estimated 350 - than died in combat, a U.S. defense official said.

That trend appears to have held in 2013 although preliminary data is showing a slight improvement, with 284 suicides among active duty forces in the year to December 15, the official added.

McRaven's command, headquartered at MacDill Air Force Base in Tampa, oversees elite commandos operating in 84 countries.

The Army, Navy, Air Force and Marine Corps special operations commands comprise about 59,000 people, according to Pentagon documents. Special operations forces have been lionized in popular culture in recent years, in movies such as "Zero Dark Thirty," about the hunt for bin Laden, and "Act of Valor," as well as a National Geographic special.

Kim Ruocco, who assists the survivors of military members who commit suicide, said members of the closely knit special operations community often fear that disclosing their symptoms will end their careers.

Additionally, the shrinking size of the U.S. armed forces has put additional pressure on soldiers, whose sense of community and self-identity is often closely tied to their military service, said Ruocco, director of suicide prevention programs for the Tragedy Assistance Program for Survivors, an advocacy group for military families.

Florida