South Korea’s president said Wednesday that President Trump “deserves big credit” for renewed talks between South and North Korea, and that Mr. Trump has offered to negotiate personally with North Korean leader Kim Jong-un. “It could be a resulting work of the U.S.-led sanctions and pressure,” President Moon Jae-in told reporters. “I think President Trump deserves big credit for bringing about the inter-Korean talks.” Mr. Trump told Mr. Moon in a phone call that he is open to talking with North Korea, the South’s presidential office said. Mr. Trump also said there would be no military action while talks are ongoing, the statement said. The White House said that Mr. Moon thanked the president “for his influential leadership in making the talks possible.” The North-South talks, held on Tuesday, were the first in two years, and North Korea announced that it would send a delegation to the Olympics in Pyeongchang next month. Mr. Trump said Vice President Mike Pence will lead the U.S. delegation to the games. In their phone call, the White House said the two leaders “underscored the importance of continuing the maximum pressure campaign against North Korea.” “President Trump expressed his openness to holding talks between the United States and North Korea at the appropriate time, under the right circumstances,” the White House said. Mr. Moon said he wanted to show Mr. Trump his gratitude. Mr. Trump tweeted last week that he believes his pressure on Pyongyang has produced results. “Does anybody really believe that talks and dialogue would be going on between North and South Korea right now if I wasn’t firm, strong and willing to commit our total ‘might’ against the North,” the president tweeted, adding that “talks are a good thing!” Mr. Trump has raised the pressure on North Korea for the past year, pressing China to isolate Pyongyang economically and diplomatically. He also has imposed new U.S. sanctions and gained new U.N. sanctions against North Korea over its nuclear and intercontinental ballistic missile programs. Former U.N. Ambassador John Bolton, an ally of the administration, said on Twitter that the North-South talks “are a waste of oxygen.” “We’ll have scenes of the two Koreas parading on TV at the Olympic opening ceremony, but as far as the North Korea nuclear threat is concerned, it won’t change a thing,” Mr. Bolton said.