An average of one US soldier a day has committed suicide this year so far the highest rate since the US went to war in Afghanistan and Iraq -according to data released Friday by the Pentagon.

The data showed that there had been 154 military suicides in the first 155 days of 2012 - 18 per cent more than in the same period of 2011.

The suicide trend prompted Secretary of Defence Leon Panetta to issue a memorandum to the country's top leadership in May that called suicide "one of the most complex and urgent problems" facing the military.

Panetta noted the stigma often connected with seeking help for mental-health issues and insisted that commanders and supervisors reach out to soldiers who appear to be suffering, and show no tolerance for "actions that belittle, haze, humiliate or ostracize" anyone in need of help.

The war in Afghanistan, which began in 2001, is one of the longest wars waged in US history, longer than World War II and the Civil War. Many soldiers have been deployed multiple times, often for a year or more at a time, and suffer post-traumatic stress disorder which often goes undiagnosed or untreated.

"The continual rise in the suicide rate has frustrated all in the military," Elspeth Ritchie, a retired army colonel and chief psychiatric adviser to the army surgeon general, told Time magazine.-Sapa