Turkish President Recep Tayyip Erdogan said Monday that his army was ready to launch operations against Kurdish militants in Syria at any moment following the US announcement that it would not stand in the way.
"There is a phrase that we always say: we can come any night without warning," Mr Erdogan told reporters in televised remarks.
"It is absolutely out of the question for us to further tolerate the threats from these terrorist groups," he said, referring to Kurdish militants.
The White House on Sunday said Turkey would "soon be moving forward with its long-planned operation" in northern Syria.
It also said Turkey would be "responsible for all ISIS fighters in the area captured over the past two years," using an acronym for the Islamic State group.
Mr Erdogan said he would work with European governments to deal with foreign Islamic State prisoners in the region.
"There are (IS prisoners) from France, Germany, other countries. They say 'We don't want to have control over them,'" Mr Erdogan said.
"We can't look after them. What can be done about this? They are going to work on that and I instructed our colleagues to work on that too," he added.
The Kurdish-led Syrian Democratic Forces (SDF) says a Turkish attack against them could reverse years of successful operations to defeat the Islamic State group and allow some of its surviving leaders to come out of hiding.
The SDF holds thousands of Islamic State fighters and their families in prisons and informal settlements across northern Syria.
It has been a key US ally against the Islamic State group but is seen by Ankara as a "terrorist" offshoot of Kurdish insurgents inside Turkish territory.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)