Meanwhile, the top nuclear envoys of South Korea, the U.S. and Japan met Tuesday in New York and reaffirmed their three-way cooperation on North Korea nuclear issues.
That's Seoul's chief nuclear negotiator, Lee Do-hoon and his U.S. and Japanese counterparts -- Stephen Biegun and Shigeki Takizaki.
This was their first trilateral since Takizaki was appointed nuclear envoy earlier this month.
Earlier the same day, the national security advisors of South Korea and the U.S. also met on the same issue.