WASHINGTON (AFP) - A US soldier who fought off an "onslaught" of Afghan insurgents despite wounds to his arm and legs received the country's highest military honour on Monday at a White House ceremony.

Ryan Pitts, a retired US Army staff sergeant, was hailed by President Barack Obama for keeping a huge force of Taleban at bay in one of the bloodiest battles of the 13-year-war in Afghanistan.

"Machine gunfire and mortar and rocket propelled grenades poured down from every direction," said Mr Obama, recounting a Taleban ambush near the village of Wanat on July 19, 2008.

"Against that onslaught, one American held the line," Mr Obama said of Staff Sgt Pitts.

Only the eighth living recipient to receive the Medal of Honour, Staff Sgt Pitts was lauded for his role in a controversial battle. The ambush, which left nine soldiers dead and 27 wounded, sparked accusations that senior officers had overextended American forces in the area.

A military investigation later concluded commanders were negligent and slow-moving, having sent troops to a distant, rugged location without enough support. But the Army overruled the probe and did not reprimand the responsible officers.

Staff Sgt Pitts and his fellow soldiers had only recently arrived at the outpost in eastern Nuristan province and were still building its defences when the ambush erupted in pre-dawn darkness from the surrounding hills.

Staff Sgt Pitts was hit by grenade shrapnel and had to be given a tourniquet to stop the bleeding, according to the army's account of that day.

"Unable to stand, Ryan pulled himself up on his knees and manned a machine gun," Mr Obama said.

He hurled one grenade after another to fend off the insurgents, but the Taleban continued to move closer and closer to his outpost.

Staff Sgt Pitts soon realised he was the only soldier alive at the post, and issued a desperate call for help over his radio.

"The enemy was so close, Ryan could hear their voices. He whispered into the radio - he was the only one left and was running out of ammo," Mr Obama said.

Reinforcements finally arrived and Staff Sgt Pitts was able to call in air strikes, with bombs landing dangerously close.

The outpost and nearby base that was attacked that day was part of a larger US effort to disrupt supply routes used by insurgents with sanctuaries across the border in Pakistan. After the battle, the Wanat base was closed.

In an interview with the Army Times, Staff Sgt Pitts, now 28, said the medal belonged to all the soldiers he served with.

"I'm going to receive it, but it's not going to be mine. We did it together. No one guy carried that day," Staff Sgt Pitts said.

And the medal was "also a memorial to the guys who didn't come home."