Mr Trump was asked on Friday about the vow he repeatedly made on the campaign trail during an interview for the Full Measure television program as his administration is still trying to broker a solution 54 days into his second term.
"Well, I was being a little bit sarcastic when I said that," Trump said in a clip released ahead of the episode airing on Sunday.
"What I really mean is I'd like to get it settled and ... I'll be successful."
It was a rare admission from Trump, who has a long record of making exaggerated claims.
At a CNN town hall event in May 2023, the prospective candidate said: "They're dying, Russians and Ukrainians. I want them to stop dying. And I'll have that done - I'll have that done in 24 hours."
"That is a war that's dying to be settled. I will get it settled before I even become president,"Trump said during his September debate with then-vice president Kamala Harris.
"If I win, when I'm president-elect, and what I'll do is I'll speak to one, I'll speak to the other. I'll get them together."
He repeated the claim frequently on the campaign trail.
His special envoy Steve Witkoff, was in Moscow this week for talks on a US-proposed ceasefire, which Ukraine has accepted.
In the interview, Trump was also asked what the plan would be if Vladimir Putin does not agree to a ceasefire to the war he started three years ago.
"Bad news for this world because so many people are dying," Trump said.
"But I think, I think he's going to agree. I really do. I think I know him pretty well and I think he's going to agree."
