North Korean leader Kim Jong Un has promised the unidentified "gift" -- which could be a missile test -- if the US does not make concessions in nuclear talks by the end of the year.

"We'll find out what the surprise is and we'll deal with it very successfully," Trump told reporters at his Mar-a-Lago resort in Florida.

"Everybody's got surprises for me, but let's see what happens. I handle them as they come along."

"Maybe it's a nice present, maybe it's a present where he sends me a beautiful vase as opposed to a missile test," the president joked.

Talks on denuclearization as been largely deadlocked since a second summit between Trump and Kim in Hanoi collapsed at the start of this year.

Pyongyang has issued a series of increasingly assertive comments as its time limit approaches.

It has carried out a series of static tests at its Sohae rocket facility this month, after a number of weapons launches in recent weeks.