"I don't think in terms of winning and losing. I think in terms of getting it settled," Mr Trump said at the first televised CNN town hall of the 2024 US presidential election in the state of New Hampshire.
"I want everybody to stop dying. They're dying. Russians and Ukrainians. I want them to stop dying. And I'll have that done," Mr Trump said, opposing the establishment Republican policy of backing Ukraine.
"I'll have that done in 24 hours. I'll have it done. You need the power of the presidency to do it," Mr Trump said.
Earlier in the town hall, Mr Trump insisted that he could halt the war that started in February last year by negotiating directly with Russian leader Vladimir Putin and Ukrainian leader Volodymyr Zelenskyy.
"I'll meet with Putin. I'll meet with Zelensky. They both have weaknesses and they both have strengths. And within 24 hours, that war will be settled. It'll be over," Mr Trump said.
At another moment, Mr Trump declined to say if he believes that Mr Putin is a war criminal for alleged atrocities committed in Ukraine.
"If you say he's a war criminal it's going to be a lot tougher to make a deal to make this thing stopped," he said.
"If he's going to be a war criminal, people are going to grab him and execute him, he's going to fight a lot harder than he's fighting under the other circumstance. That's something to be discussed at a later day."
The former president also said he thinks that "Putin made a mistake" by invading Ukraine. When asked to elaborate, Mr Trump said, "His mistake was going in. He would have never gone in if I was president."
Mr Trump, 76, has already announced his bid for a 2024 comeback and is a frontrunner to be the Republican Party's nominee, despite having been criminally indicted and remaining under multiple other investigations on serious allegations.
Here's what he said about the sexual abuse verdict
An unrepentant Mr Trump also held firm to past grievances, making clear from the moment he took the stage that he has little intention of mounting a more disciplined campaign for his third White House bid.
In a contentious 70-minute broadcast on CNN on Wednesday, Mr Trump drew laughter from a New Hampshire audience when he mocked writer E Jean Carroll's account of his having sexually abused her.
On Tuesday, a federal jury found Mr Trump sexually abused Ms Carroll in a department store dressing room in Manhattan in the 1990s, then harmed her reputation by describing her claims as "a hoax" and "a lie".
"What kind of a woman meets somebody and brings them up and within minutes, you're playing hanky panky in a dressing room?" Mr Trump said, one of many disparaging comments about Ms Carroll that elicited applause and laughter.
He called her a "wack job".
Mr Trump, who was absent throughout the two-week trial, was asked by an audience member what he had to say to voters who say it disqualifies him from being president. "Well, there aren't too many of them because my poll numbers just came out. They went up," he said.
Refuses to accept 2020 electoral defeat
He also repeated lies about his 2020 election loss and said he would pardon many of his supporters convicted of taking part in the 6 January 2021 attack on the Capitol and called his moderator Kaitlan Collins a "nasty person".
Responding to questions from Ms Collins and members of the audience at Saint Anselm College, Mr Trump made no effort to offer more moderate positions on issues, which political analysts say is key to broadening his appeal to a wider group of Republicans.
Asked by Ms Collins whether he would acknowledge that he lost to Democrat Joe Biden in 2020, Mr Trump reasserted unfounded claims that the election was rigged against him, brushing aside her attempts to correct the record.
"That was a rigged election," Mr Trump said, adding that anyone who thought otherwise was "stupid".
Vows to pardon supporters convicted of Capitol Hill attack
Mr Trump, the frontrunner in the race for the Republican nomination, declined to express regret for the deadly attack on the Capitol when supporters sought to prevent Congress from ratifying the election result, and he repeated his plan to pardon individuals involved if voters return him to the White House in 2024.
"I am inclined to pardon many of them. I can't say for every single one because a couple of them, probably, they got out of control," Mr Trump said.
The audience of Republicans and independent voters who plan to vote in the Republican primary were generally very supportive of Mr Trump, giving him a standing ovation when he took the stage.
New Hampshire is an early nominating state that could prove critical in his bid to return to the White House.
