It was the first such talks between the two countries in two years, with Seoul hoping for further dialogue that might lead to reunions between families divided by decades-old standoff.
In the latest tweet to ratchet up tensions with Pyongyang, the president responded to the North Korean leader's New Year's address, in which he warned that his missiles could reach all of the U.S.
Putting regional pressure on the Kim Jong Un regime is expected to be the main push of the five-country tour that includes Japan, South Korea, China, Vietnam and the Philippines.
New Yorker writer Evan Osnos visited North Korea in August to understand what they really mean when they talk about nuclear war. He found that nuclear weapons are an essential part of their society.
Last week, a North Korean missile flew over Japan's northern island of Hokkaido. Normally a peaceful place known for its ski resorts, its residents are rethinking the threat.
Washington's ambassador to the United Nations Nikki Haley called on the U.N. Security Council to impose "the strongest possible measures" on Pyongyang after its latest nuclear weapon test.