Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. US Defense Chief in Iraq to Discuss Operation to Retake Mosul by VOA News U.S. Defense Secretary Ash Carter arrived in Iraq Saturday to meet with coalition commanders to review and assist the operation to retake Mosul from Islamic State militants. The secretary is on his third visit to Iraq this year. He is overseeing the U.S.-backed operation led by Iraqi forces in their battle to push the jihadists out of the region. Carter's unannounced visit to Baghdad comes after an American soldier was killed in the region a few days ago. The defense secretary is also scheduled to meet with Iraqi Prime Minister Haider al-Abadi. They are likely to discuss Baghdad's reluctance to include Turkish forces in the Mosul operation. On Friday, Carter and Turkish President Recep Tayyip Erdogan met in Ankara to discuss the need to increase military cooperation between the U.S. and Turkey in the campaign to defeat Islamic State in both Iraq and Syria. Carter also met with other top Turkish political and defense officials. A U.S. Defense Department statement said the leaders agreed to maintain frequent communication and close coordination among members of the coalition fighting IS to ensure a "lasting defeat" of the terrorist group. Turkey wants to have a larger role in the battle for Iraq's second city, which has been under Islamic State control for more than two years, but the Iraqi government is opposed to Turkish military involvement in Mosul. The U.S. fears tensions between the two countries could lead to the end of an agreement that is keeping rival sectarian and ethnic militias out of Mosul. Before he arrived in Turkey, Carter said he would emphasize the need for Turkey to respect Iraq's sovereignty. The Turkish and Iraqi governments have been feuding about the presence of Turkish troops at the Asia camp north of Mosul where 500 Turkish soldiers have been training Sunni and Kurdish fighters since last December. The Iraqi government has said the troops do not have permission to be at the base and called for them to leave. Turkey has refused and said the soldiers will take part in the operation to retake Mosul. Carter also toured the Turkish parliament building, which was damaged during an attempted coup in July, and expressed condolences for those who were killed defending the Turkish government. "I think everyone there admires the heroes and the martyrs of that terrible incident. We are your strong friends, your long-time allies and staunch supporters of the great democracy in Turkey," Carter said.