US Secretary of State Mike Pompeo said Sunday he will meet this week in New York with North Korea's number two to discuss denuclearization.
North Korea's foreign minister told the United Nations on Saturday continued sanctions were deepening its mistrust in the United States.
United States on Friday accused Russia of violating U.N. sanctions on North Korea.
Trump said on Thursday North Korea was blowing up four of its big test sites and that a process of "total denuclearization ... has already started.
Trump warned Tuesday his landmark summit with Kim Jong Un may be delayed, but insisted the North Korean leader is "serious" about denuclearization.
U.S. Secretary of State Mike Pompeo said on Friday the complete denuclearization by Pyongyang will require "robust verification.
US President Donald Trump said Friday that a date and venue for his landmark summit with North Korea's Kim Jong Un would be unveiled soon.
President Donald Trump said on Friday he was encouraged by a historic meeting between North and South Korean leaders.
Denuclearization is not on the agenda in the meeting with North Korean, South Korean and American delegations taking place in Helsinki.
South Korea and the US vowed to keep their joint campaign of pressure to bring Pyongyang to talks on its denuclearization.