The call comes a day after representatives from North and South Korea held day-long negotiations in the demilitarized zone, where Pyongyang agreed to send a delegation to next month's Winter Olympics and to hold talks with Seoul to ease military tensions.
White House press secretary Sarah Sanders said in a statement that Moon briefed Trump on the "outcomes of the discussions between North and South Korea" and Moon "thanked President Trump for his influential leadership in making the talks possible."
Moon, during a briefing with reporters earlier, credited Trump with making a "huge" contribution to bringing the North and South together.
"The two leaders underscored the importance of continuing the maximum pressure campaign against North Korea," Sanders said. "President Trump expressed his openness to holding talks between the United States and North Korea at the appropriate time, under the right circumstances."
The South Korean readout of the call said the conversation lasted 30 minutes and the two leaders agreed to "strengthen cooperation between South Korea and the US."
Both leaders "predicted that inter-Korean dialogue could naturally lead to a possible conversation between the US and North Korea to achieve denuclearization of the Korean Peninsula beyond North Korea's participation in the Pyeongchang Olympics."
"I hope you let them know that there will be absolutely no military action as long as inter-Korean talks are ongoing," Trump said, according to the statement from the South Korean government.
That statement seemingly goes against Trump's long-expressed pledge to never telegraph military maneuvers.
The conversation with Moon is the latest in a series of moves where Trump has signaled an openness in talking with the North Korean leader.
During a conversation with reporters on Saturday at Camp David, Trump said he would "absolutely" be open to talking to Kim.
"Sure, I always believe in talking," he said. "But we have a very firm stance. Look, our stance, you know what it is. We're very firm. But I would be, absolutely I would do that. I don't have a problem with that at all."
Trump later said that didn't mean he would talk to Kim without prerequisites, but that "if something can happen and something can come out of those talks, that would be a great thing for all of humanity."
Trump's strategy with North Korea has been firm and his rhetoric has escalated since he took office in January. He promised "fire and fury" for North Korea if their nuclear program and missile tests continued and recently said his nuclear button is "bigger and more powerful" the Kim's, who he has taken to calling "Little Rocket Man."
Trump has, however, taken credit for the fact that South and North Korean negotiators met this week to discuss cooperation during the 2018 Olympics in South Korea.
"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," he tweeted earlier this month, "Fools, but talks are a good thing!"