WASHINGTON — President Donald Trump defended his actions in Syria on Wednesday as "strategically brilliant," disparaging the Kurdish allies he abandoned in the face of a Turkish offensive as "not angels."

Trump has come under intense criticism for effectively giving Turkey a green light to invade northern Syria, but he dismissed those concerns in comments to White House reporters.

He spoke as Vice President Mike Pence and Secretary of State Mike Pompeo prepared to travel to Turkey to try to persuade President Recep Tayyip Erdogan to halt the offensive.

But Trump emphasized that US troops were out of harm's way and that the fallout from the abrupt US withdrawal was for Syria, Turkey and Russia to work out among themselves.

"I view the situation on the Turkish border with Syria to be, for the United States, strategically brilliant," Trump said, alongside visiting Italian President Sergio Mattarelli.

"Our soldiers are out of there, our soldiers are totally safe. They've got to work it out," he added.

"Turkey has gone into Syria. If Turkey goes into Syria, that's between Turkey and Syria — it's not between Turkey and the United States, like a lot of stupid people would like you to believe."

Trump expressed confidence that US nuclear weapons stored at Turkey's Incirlik air base were secure, despite flaring tensions between Ankara and its NATO allies over the Syrian incursion.

And he minimized the escape of Daesh (the so-called IS) fighters who had been held by the Kurds as an attempt to "make us look like, 'Oh, gee, we have to get right back in there'."

Critics have warned that their escape gives the militants an opportunity to regroup after having lost their caliphate in Syria to US forces and their Kurdish allies.

"You have a lot of countries over there that have power and that hate ISIS (Daesh) very much, as much as we do. So I think we're in a very strategically good position," he said.

"And the Kurds are much safer right now but the Kurds know how to fight and as I said, they aren't angels. They are not angels if you take a look," he said.

Turkish forces moved into Syria last week after Trump withdrew US troops from the area. — AFP