China is urging its ally North Korea to proceed with a historic summit between its leader, Kim Jong Un, and President Donald Trump amid threats from Pyongyang to scrap the meeting.

Foreign Ministry spokesman Lu Kang said Wednesday that the sides should ensure the meeting runs as planned and yields "substantial outcomes."

Kim and Trump are due to meet in Singapore on June 12, but Pyongyang on Wednesday threatened to withdraw, saying it has no interest in a "one-sided" affair meant to pressure it into abandoning its nuclear weapons.

Lu said the meeting was crucial to reducing tensions on the Korean Peninsula and maintaining regional peace and stability.

The North's warning came hours after it abruptly canceled a high-level meeting with South Korea to protest U.S.-South Korean military exercises.