Turkey has information that the Kurdish YPG militia has not completed its withdrawal to 30 km (18.64 miles) from the Turkish border in northeast Syria, President Tayyip Erdogan said on Wednesday, despite assurances from Russia that they had left.

He told lawmakers from his AK Party that Turkey reserved the right to launch another operation against the YPG in the area.

Ankara and Moscow had agreed to remove Kurdish YPG fighters from a depth of 30 km south of the border inside Syria by late on Tuesday and Russia told Turkey that the YPG had left the strip within the 150-hour deadline.

"Even though the information in our hands suggests this has not been succeeded in a full sense, we will give our response to them after our field assessments," he said.

Joint patrols had been set to begin on Tuesday at a depth of 10 km, but Erdogan said in Wednesday's speech that the patrols would begin on Friday and at a depth of just 7 km.

"If we see that the members of the terrorist organisation have not been moved out of the 30 km, or if attacks continue, no matter from where, we reserve our right to carry out our own operation," he said.

Earlier, Defence Minister Hulusi Akar was quoted by state-owned Anadolu Agency as saying that talks between Turkish and Russian officials, ongoing since Monday, had concluded and the two delegations had "largely" reached an agreement.

Turkey views the YPG as a terrorist organisation because of its links to Kurdish militants in southeast Turkey. Ankara launched an offensive against the formerly U.S-allied YPG following President Donald Trump's abrupt withdrawal of 1,000 American forces from northern Syria in early October.