US soldier killed in action in Afghanistan

A US soldier was killed in action in Afghanistan on Thursday, NATO said, marking the seventh American service member to die in the war-torn country this year.

The soldier had been assigned to NATO's Resolute Support mission, which trains and assists Afghan security forces.

An investigation was under way into the soldier's death, NATO said.

General Joseph Votel, who heads the US military's Central Command, said initial reports indicate the death was as a result of "combat action", but no additional information was immediately available.

"Our thoughts go out the soldier's family and to the unit that he came from," Votel told Pentagon reporters. 

Also Thursday, the Taliban issued a statement claiming it had blown up a US armoured vehicle in Garmser district in the southern province of Helmand, killing the soldiers on board.

The incident could not be immediately verified. 

Currently, there are about 14,000 US troops in Afghanistan, providing the main component of the NATO mission there to support and train local forces. 

More than 2,000 American soldiers have been killed in Afghanistan since the start of the war in 2001.

While casualties have fallen dramatically since the withdrawal of US-led NATO combat troops at the end of 2014, the deadly burden has shifted to Afghanistan's security forces.

The Kabul government no longer releases death tolls, but the Taliban are thought to be killing thousands of Afghan army and police forces each year.

Votel acknowledged the number is rising.

"It's my understanding that it is increasing," he said.

"This is something that we are paying very, very close attention to," Votel added, noting that the Afghan forces are still "sustaining themselves" in terms of replacing those lost in combat.