The top U.S. envoy for North Korea agreed with senior officials of the Foreign Ministry on Wednesday to continue working closely together amid a standstill in denuclearization talks with Pyongyang.

Stephen Biegun and Vice Foreign Minister Takeo Akiba confirmed the importance of trilateral cooperation with South Korea in dealing with the North during their meeting in Tokyo, the ministry said.

Earlier in the day, Biegun met with Shigeki Takizaki, the ministry's head of Asian and Oceanian affairs, discussing issues including North Korea's abductions of Japanese nationals during the 1970s and 1980s. He also met with Shigeru Kitamura, Prime Minister Shinzo Abe's national security adviser.

Pyongyang has been ramping up its provocative rhetoric in recent weeks, warning it will resume nuclear and intercontinental ballistic missile tests if there is no breakthrough in negotiations with Washington by year-end.

Biegun, who was nominated by U.S. President Donald Trump for the post of deputy secretary of state, is on a tour of Northeast Asia that took him to Seoul and will see him visit Beijing later this week.

He is believed to have been exploring the possibility of meeting with North Korean officials in the inter-Korean truce village of Panmunjom.