It is supposed that Mr. Carter visited troops and met with Iraqi officials in order to estimate the result of the military campaign and plan further actions.

The US has been supporting the Iraqi security forces by means of air attacks since August 2014. However, the US excludes the possibility of sending troops to Iraq. Several cities and other territory in northern and western parts of Iraq are still under the ISIS control.

At the same time, Mr. Carter has focused on getting allies such as Turkey, where he visited Tuesday, to “do more.” The US wants Ankara to agree to seal a portion of its border with Syria to stop the flow of foreign fighters in and out of Syria.

“In general, we need Turkey, like other members of the coalition, to step up and do more. Because of their geography, they have a special role to play, that’s why we’re grateful to have them hosting here, but they also need to secure their border,” Mr. Carter said.

Saudi Foreign Minister Adel al-Jubeir said on Tuesday that a new Saudi-led Islamic alliance to fight terrorism will share information and train, equip, and provide forces if necessary for the fight against Islamic State militants. "Nothing is off the table," al-Jubeir said when asked whether the initiative could include troops on the ground.