An insurgent attack in volatile eastern Afghanistan killed three foreign soldiers on Sunday, a statement said.

The deaths bring the number of fatalities among foreign troops this year to 114, according to the independent icasualties.org website, which recorded 402 such deaths in 2012.

"Three International Security Assistance Force service members died following an enemies of Afghanistan attack in eastern Afghanistan today," said the statement from the NATO-led International Security Assistance Force (ISAF).

In line with ISAF policy, nationalities were not given and casualty identification was left to the relevant nation.

International military casualties have fallen in recent months as the Afghan army and police take the lead in the battle to thwart the Taliban insurgency. But areas of the south and east remain highly dangerous.

ISAF total troop numbers fell from 98,000 to 87,200 between June 24 and August 1, according to official figures, with all combat soldiers due out of the country by the end of next year.

About 60,000 of the coalition troops deployed in Afghanistan are from the US.