At least three foreign soldiers were killed Monday when a Taliban suicide bomber on a motorcycle attacked a joint NATO-Afghan patrol near Bagram airbase outside Kabul, officials said.

"The attack left three coalition soldiers dead and two others wounded. Three Afghan policemen were also injured in the attack," said Mohammad Asem, governor of Parwan province where the airfield is located.

A security official in Bagram district gave a higher toll, saying five foreign soldiers had been killed and six others had been wounded. The nationalities of the troops were not immediately known.

In a brief statement NATO confirmed the attack but gave no details.

"There has been a vehicle-borne improvised explosive device attack in the vicinity of Bagram Air Field. At this time, the incident is under investigation," it said.

The Taliban claimed responsibility, with a spokesman claiming on Twitter that 19 US soldiers had been killed.

The insurgents are known routinely to exaggerate battlefield claims.

The Taliban are ramping up attacks on government and foreign targets despite the onset of the harsh winter season, when the fighting usually calms down.

This month marks a year since the US-led NATO mission in Afghanistan transitioned into an Afghan-led operation, with allied nations withdrawing from the frontline and instead helping to train and advise local forces.

President Barack Obama in October announced that thousands of US troops would remain in Afghanistan past 2016, backpedalling on previous plans to shrink the force and acknowledging that Afghan forces are not ready to stand alone.