A US Navy Seal has been killed in an Islamic State group attack near the Iraqi city of Mosul, according to US defence officials.

The service member was killed by "direct fire" after IS militants penetrated the Kurdish Peshmerga line on Tuesday morning, said the officials.

Pentagon press secretary Peter Cook said the Navy Seal was advising and assisting Peshmerga forces when they came under attack between two and three miles behind the front line.

Mr Cook said: "This sad news is a reminder of the dangers our men and women in uniform face every day in the ongoing fight to destroy ISIL and end the threat the group poses to the United States and the rest of the world.

"Our coalition will honour this sacrifice by dealing ISIL a lasting defeat."

Defence Secretary Ash Carter said: "It is a combat death, of course."

Mosul, Iraq's second-largest city, has been in the hands of IS militants since they overran large swathes of northern and western Iraq in 2014.

US Vice President Joe Biden visited Baghdad last week to push leaders in the Iraqi government to resolve internal political strife and concentrate on defeating IS.

It is the third death of a US service member since the US-led coalition operation began against IS in 2014.

In March, a US Marine stationed at Makhmour base outside Mosul was killed in a rocket attack.

A special operations soldier was killed in a firefight in October 2015 during a raid on an IS prison in Iraq.