U.S. Special Representative for North Korea Stephen Biegun held a closed-door meeting with members of the United Nations Security Council on Wednesday amid stalled denuclearization negotiations with Pyongyang.

Biegun met with envoys from the 15 Security Council member states at the U.S. mission to the UN and discussed recent developments regarding North Korea.

According to a diplomatic source who attended the meeting, Biegun referred to a letter that North Korean leader Kim Jong-un recently sent to U.S. President Donald Trump and Kim's offer of condolences over the death of the widow of former South Korean President Kim Dae-jung as "positive signals."

South Korea's Permanent Representative to the UN Cho Tae-yul also attended the meeting as a representative of a relevant party to Korean Peninsula issues.

Cho told reporters that the participants discussed their assessments of the current situation and what direction they should take in relation to future negotiations with North Korea.

The sanctions issue was also reportedly raised during Wednesday's meeting. The U.S. has maintained that all sanctions on North Korea must be enforced until the regime denuclearizes.