Ankara has complained over the slow implementation of a deal with Washington to pull YPG terrorists out of Manbij, which lies in mainly Arab territory west of the Euphrates in Syria, back to the eastern bank of the river.
Turkish forces will enter the Syrian town of Manbij if the United States does not remove YPG terrorists from the area, and also target militant-controlled areas further east, President Recep Tayyip Erdogan said on Friday.
Erdogan said this week that Turkey would launch a new operation within days against the US-backed YPG which controls swathes of Syria's northern border region, in what will be Turkey's third military campaign in Syria in two years.
Ankara and Washington have long been at odds over Syria, where the United States has backed the YPG in the fight against Daesh. The YPG is the Syrian branch of the PKK terror group.
"We are now calling on the US to clear Manbij once and for all so that the rightful residents can go back to their own lands. Or else we will walk into Manbij," said Erdogan.
"Turkey has wasted enough time by not intervening in the swamp of terror to the east of the Euphrates."
"From now on, we will not tolerate even one day of delay in the clearance of Manbij," he said.
Telephone call with Trump
In a telephone conversation between Erdogan and US President Donald Trump on Friday evening, bilateral issues and the most recent developments in Syria, including security issues and counter-terrorism efforts, were discussed.
Erdogan shared with Trump Turkey's legitimate security concerns caused by the presence and actions of the terrorist PKK/PYD/YPG group.
The two leaders agreed on the need for more effective coordination within the context of Syria.
Turkey-US deal on Manbij
Turkey has complained over the slow implementation of a deal with Washington to pull YPG militants out of Manbij, which lies in mainly Arab territory west of the Euphrates, back to the eastern bank of the river.
"Manbij is a place where Arabs live, but they have surrendered the area to the terror organisation," Erdogan told members of the Organisation of Islamic Cooperation in a speech in Istanbul.
"Now we are saying that you should cleanse, remove them, or else we will enter Manbij. I am speaking very clearly."
Erdogan said Turkey was also determined to bring "peace and security" to areas east of the Euphrates, where the YPG controls an area stretching more than 400 kilometres (250 miles) along the border towards Iraq.
He compared the promised military campaign to an incursion into northern Syria in 2016 and one earlier this year by Turkish forces and their Syrian opposition allies, who still hold territory there seized from YPG and Daesh militants.
A spokesman for the Syrian opposition said on Thursday that up to 15,000 fighters are prepared to support Turkey's latest operation.
The United States, which has set up observation posts on the Syrian side of the border, has opposed Turkey's planned operation and said the newly constructed positions would help deter any security threat against Turkey coming from Syria.
Erdogan, however, said Turkey had waited long enough to act against the YPG/PKK.
"We are not only providing security for our country when taking steps in Syria but we are also protecting the honor of people," he said.
In its more than 30-year terror campaign against the Turkish state, the PKK - listed as a terrorist organization by Turkey, the US and the EU - has been responsible for the deaths of some 40,000 people, including women and children.
The PKK's Syrian branch, YPG, has occupied the Syrian region east of the Euphrates, which shares a 480-kilometer-long (298 miles) border with Turkey.