Baghdad, Oct 23 (IANS): US Defence Secretary Mark Esper on Wednesday made a surprise visit to Baghdad, two days after a convoy of US troops withdrawing from Syria crossed into Iraqi Kurdistan.

A government source said that Esper held an early morning meeting with his Iraqi counterpart Najah al-Shammari at the headquarters of the Iraqi ministry of defence to discuss joint action to combat the Islamic State terror organisation, Efe news reported.

The US official is scheduled to meet with the troops that entered the semi-autonomous Kurdistan region on Monday.

On Tuesday, the Iraqi military said the US troops leaving Syria amid the Turkish offensive were not permitted to stay in Iraq and would later be transferred outside the country.

The Russian military police and Syrian regime border guards agreed Tuesday to clear the Syrian People's Protection Units (YPG) from the 30-kilometer deep buffer zone sought by Ankara within a period of 150 hours.

The Russia-Turkey pact came a few hours before the expiry of a five-day ceasefire agreed on 17 October in Ankara with a US delegation.

Turkey launched an offensive in the northeastern Syrian border on 9 October shortly after the US President Donald Trump announced the withdrawal of the remaining troops from the region.

Ankara considers the YPG to be a terror group indistinguishable from the Kurdistan Worker's Party (PKK), a guerrilla group widely listed as a terror organization that has fought the Turkish state in the country's predominantly Kurdish east for decades.