UNITED NATIONS (Reuters) - Russia's U.N. Ambassador Vassily Nebenzia said on Monday that "the Ukrainian crisis cannot be solved in one day," when asked about U.S. presidential candidate Donald Trump's frequent claims that he could end the war within 24 hours if reelected.

Republican candidate Trump has not given any details and has said that if there had been a "real president" in the U.S. - who was respected by Russian President Vladimir Putin - then Moscow would not have invaded Ukraine in February 2022.

"I will have that war settled between Putin and (Ukrainian President Volodymyr) Zelenskiy as president-elect before I take office on January 20th. I'll have that war settled," Trump said last week during a debate against President Joe Biden, a Democrat. "I'll get it settled fast, before I take office."

U.S. voters go to the polls on Nov. 5 to elect the next president for a four-year term.

The outcome of the election matters to Russia, despite its attempts to play it down, because it will determine the extent of Washington's commitment to keep backing Ukraine against Moscow and supplying it with advanced U.S. weapons.

"The Ukrainian crisis cannot be solved in one day," Nebenzia told a news conference to mark the beginning of Russia's presidency of the United Nations Security Council for July.

Trump's campaign did not immediately respond to a request for comment on Nebenzia's remarks.

The Kremlin has said that any peace plan for Ukraine proposed by a possible future Trump administration would have to reflect the reality on the ground but that Putin remained open to talks.

(Reporting by Michelle Nichols; editing by Jonathan Oatis)

By Michelle Nichols