Republican presidential candidate Haley campaigns in Bedford
Republican presidential candidate and former U.S. Ambassador to the United Nations Nikki Haley speaks during a campaign town hall meeting in Bedford, New Hampshire, U.S., April 26, 2023. Reuters

Republican presidential hopeful Nikki Haley, U.N. ambassador under former President Donald Trump, went after her ex-boss and 2024 rival Ron DeSantis on Sunday over their refusal to say whether they want Ukraine to win its war against Russia.

In recent town hall events, Trump, the favorite for the Republican presidential nomination, said that he wanted the war to end, but that he would help Ukraine and Russia negotiate a settlement.

Florida Governor DeSantis, Trump's nearest rival for the Republican nomination, said recently that he supports a settlement to the war, and that he hopes fighting will end by the time the next president takes the oath of office in January 2025.

Haley, the only woman in the race for the Republican nomination, lambasted DeSantis for saying this year that Ukraine was a "territorial dispute", a comment that drew widespread criticism and that he has since walked back.

"For them to sit there and say that this is a territorial dispute - that's just not the case, or to say that we should stay neutral," Haley told voters in the early nominating state of Iowa during a televised CNN town hall event.

"It's in the best interest of our national security for Ukraine to win," she added.

Ukraine is an issue that divides Republicans, because of an isolationist streak among many of the party's primary voters.

Haley, 51, a former South Carolina governor, declared her White House bid in February but finds herself in a crowded Republican field that will reach double digits this week with the entrance of more contenders, including former Vice President Mike Pence.

Trump dominates the field among potential Republican primary voters with 49% support. DeSantis is next with 19%. There is a yawning chasm between them and the rest of the field, including Haley; she has just 4% support, according to the latest Reuters/Ipsos opinion poll conducted in May.

Haley and many of her rivals polling in single digits are trying to differentiate themselves from DeSantis, in the hope that he stumbles and they can become the main alternative to Trump.

But some have also begun to criticize Trump himself, after months of shrinking away from attacking the former president out of a fear of alienating his hardcore supporters.

On Sunday she also criticized Trump for congratulating North Korean leader Kim Jong Un last week after the country was elected to the executive board of the World Health Organization. Trump has also praised the North Korean leader in the past.

"Kim Jong Un is a thug," Haley said. "I don't think we should congratulate dictators."

Trump also took fire from DeSantis and Pence over congratulating Kim, in separate weekend events in Iowa, the state that kicks of the nominating battle next year.