A US occupation troop was killed in Iraq, the first such incident since America announced its forces would withdraw by the end of this year.

A US occupation troop was killed in Iraq, the first such incident since America announced its forces would withdraw by the end of this year.

"A US service member was killed Thursday while conducting operations in northern Iraq," the US military said in a brief statement, without providing further details.

Thursday's death brings to 4,478 the number of US soldiers who have been killed in Iraq since the 2003 invasion, according to an AFP tally based on data compiled by icasualties.org.

US President Barack Obama announced on October 21 that US forces would leave by the end of this year, after negotiations between Washington and Baghdad on a post-2011 US military training mission fell through.

Since the US-led invasion of Iraq in 2003, bombings and other forms of violence escalated, claiming the lives of over one million people.

Earlier, Iraqi cleric, Sayyed Moqtada al-Sadr, warned that the US sought to maintain its occupation of Iraq through keeping trainers and private contractors in the country, arguing that the security situation was disturbed.

Last month, Sadr accused the Americans of creating chaos and sectarian strife in the Arab country in order to prolong their stay.