In an unprecedented move, insurgents abduct an American soldier in troubled eastern Afghanistan where coalition troops have lost several grounds to the Taliban.

The US military headquarters in Kabul confirmed that the soldier has been missing from his base since Tuesday.

The military said it would not provide further information about the missing soldier or the province in which he has gone missing.

"We are exhausting all available resources to ascertain his whereabouts and provide for his safe return," a US military statement said Thursday.

US military spokeswoman Captain Elizabeth Mathias said she believed that the soldier had been captured by militants operating in the region

This is while a commander of the Taliban's Haqqani faction said that his men had captured one US and three Afghan soldiers in Paktika Province, which borders Pakistan.

The militants have said they will soon announce their demands and conditions for releasing the American soldier.

In recent months, US-led troops have lost control over several districts in the southern and eastern provinces of Afghanistan, prompting the US military to launch a major operation against Taliban insurgency in the lower Helmand River valley.

JR/HGH