SEOUL, South Korea – South Korea's newly elected president vowed on Wednesday to play a more assertive role in resolving North Korea's nuclear crisis through dialogue, saying that he was willing to meet with its leader, Kim Jong Un, if the circumstances were right.

President Moon Jae-in also pledged to strengthen the alliance with Washington, expressing an eagerness for an early summit meeting with President Donald Trump, whose military posturing and diplomatic overtures toward the North have both rattled and confused South Koreans.

But Moon also hinted at balancing diplomacy between the U.S. and China, his country's largest trading partner, over the deployment of a U.S. missile defense system here.

Trump called Moon hours after he was formally sworn in on Wednesday. The two leaders agreed to maintain a strong alliance and to hold a summit in Washington at the earliest opportunity, it said.

"The alliance with the United States is and will always be the foundation of our diplomacy and national security," Moon was quoted as telling Trump.

New York Times