WASHINGTON

US President Donald Trump said Thursday that he would "probably" return to the US on Friday, but suggested there is still some lingering uncertainty about his plans.

"We'll be leaving tomorrow morning, as you know, almost destination unknown," he told reporters in Abu Dhabi, on what is the final publicly scheduled stop on his Middle East tour.

But he said he is "probably going back to Washington, DC."

The comments come amid speculation that Trump could drop in on Ukraine-Russia peace talks in Istanbul, though the prospects of the visit appeared to dip significantly after Russian President Vladimir Putin rolled out the Kremlin's official delegation. Notably absent from that list was the Russian president.

Trump made his presence contingent on Putin attending the talks in-person.

"I'm not disappointed in anything," Trump said earlier in Qatar when asked if he was disappointed in the more junior-level delegation Putin announced.

"Obviously, he wasn't going to go. He was going to go, but he thought I was going to go. He wasn't going if I wasn't there. And I don't believe anything is going to happen, whether you like it or not, until he and I get together. But we're going to have to get it solved because too many people are dying," he added.