NEW YORK (AP) Fifty years after the Korean war, and six months after leaders of the communist North and capitalist South held a first-ever summit, North Korea U.N. ambassador took a small but telling step of his own.

Li Hyong-chol walked through the portals of Columbia University on Dec. 1 to meet more than 250 South Korean students and press for rapid reunification of the country.

"I was happy to accept the invitation," Li told the students, "not to speak as a representative of our government at the United Nations but as a member of the same nation."

Until a half-hour before Dec. 1 afternoon? meeting, the Korean Graduate Students at Columbia doubted that Li would show up, even though he had accepted their invitation to speak about the prospects for reunification after the June summit.

"When I confirmed he was on the way, I was so happy," said Kim Hyeong-chan, the group? president, who is studying medicine.

Li said that since the June summit, "the situation is really excellent and the whole nation is excited. Everybody is full of conviction that the country is moving ahead, advancing very rapidly toward reunification."

The insisted on giving his speech in Korean, but he ended with a brief synopsis in English and then answered some tough questions in English from the students.

Asked about the U.S troops in South Korea, he said no foreign troops on Korean territory can be justified. In a united Korea, "we will calculate how to remove" them, he said to a smattering of applause.