US Defense Secretary Ash Carter said on Tuesday that an American serviceman has been killed in Iraq, describing it as a "combat death", ABC News reported.

The defense secretary, who spoke to reporters in Stuttgart, Germany, where he has been consulting with European allies this week on fighting Daesh group, provided no other details.

It was not immediately clear when the serviceman died but Pentagon Press Secretary Peter Cook said he was killed near Mosul, Iraq's second-largest city that has been in the hands of Daesh militants since they overran large parts of northern and western Iraq in 2014.

"A Coalition service member was killed in northern Iraq as a result of enemy fire," the US Central Command, or CENTCOM, said in a statement. "Further information will be released as appropriate." 

Meanwhile, a US military official in Iraq said the American was killed while performing his duty as an adviser to the Kurdish peshmerga troops. 

Source : MENA