United States National Security Advisor Jake Sullivan raised concerns about North Korea's recent weapons tests and growing military cooperation with Russia during talks with China's top diplomat.

A senior U.S. official said on Saturday in a telephonic briefing that Sullivan and Wang Yi discussed North Korea issues during their talks held on Friday and Saturday in Bangkok, Thailand.

The official said that the United States is deeply concerned about the North’s recent testing of weapons, the growing relationship between Moscow and Pyongyang and what that might mean for North Korean leader Kim Jong-un’s intentions.

The official added that the United States raised those concerns directly with China, given its influence on Pyongyang, and hopes these discussions will continue.

The official expressed hope that China will use its influence on North Korea for the North’s denuclearization.

Noting a visit to North Korea by Chinese Vice Foreign Minister Sun Weidong, the official said that there would be telephone discussions between Sun and U.S. officials after Sun returns home from the trip.