US Defense Secretary Mark Esper arrived in Baghdad on Wednesday amid questions about how long US troops withdrawn from northeast Syria will stay inside Iraq, stressing that "we will not wage war against our NATO ally," referring to Turkey.

Esber is expected to meet his Iraqi counterpart Najah al-Shammari and Prime Minister Adel Abdul Mahdi.

Esber's visit to Baghdad comes a day after US forces withdrew from northeast Syria to Iraq in coordination with the federal government.

Last Sunday, US Defense Secretary Mark Esper announced that 1,000 troops withdrawn from northern Syria were expected to be transferred to western Iraq.

The US official said his retreating forces would focus on helping to defend Iraq and fight IS.

"We are implementing a phased withdrawal," Esper told CNN. "Our troops will be temporarily stationed in Iraq before being repatriated. They will return home."

Asked about President Donald Trump's talk of keeping a few US troops to protect Syria's oil fields, he said the point was still under discussion.

The Iraqi army said on Tuesday that US forces had not obtained permission to stay on Iraqi soil but could only stay temporarily.

The United States currently has 5,200 military personnel in Iraq, and their distribution to a number of bases in Iraq is controversial, where Iraqi political and military forces oppose their presence and demand their withdrawal from the country.

US withdraws troops from northeast Syria to Iraq (Reuters)

Kurds and Turkey
US forces began withdrawing from Syria to coincide with the operation "spring of peace" launched by Turkey on October 9 in the region east of the Euphrates.

"We will not wage war against our NATO ally, and of course not to defend a border we have never committed to protecting," Esber said.

Esber said that the main reason for his country's cooperation with the so-called "Syrian Democratic Forces" is to fight the Islamic State, and that relationship was established during the era of former US President Barack Obama.

He said he was present during the telephone conversation between Turkish President Recep Tayyip Erdogan and US President Donald Trump on October 6.

"My Turkish counterpart told me several days before that call that they would start the process, and President Erdogan also warned us in that call that they would start this process."

Esber also rejected allegations that thousands of ISIS operatives detained in northeastern Syria had fled as a result of the Turkish operation.

He explained that they are aware of the escape of only a little more than a hundred detainees, out of 11 thousand detainees in northeastern Syria, adding, "Therefore we are not now in the case of mass flight as everyone expects."