Foreign Minister Wang Yi said "it is time to test the sincerity" of parties involved in the Korean Peninsula nuclear issue because every time the tension there eases, disturbing and harmful actions arise.
The senior diplomat made the remark this week as Pyongyang and Seoul have been engaging in dialogue while Washington and its allies have vowed tougher measures against Pyongyang.
The hard-won easing of the situation "should be cherished by all", Wang said in an interview with Hong Kong-based Phoenix TV as he was wrapping up his trip to Africa on Tuesday.
The global community should pay attention to who is pushing for peaceful settlement of the nuclear issue and who is leading it back to tension, Wang said.
Wang reaffirmed China's commitment to denuclearizing the peninsula and said progress should be made in a step-by-step approach, with the parties involved exploring other ways for potential breakthroughs.
Pyongyang has offered to send a 230-member cheering squad to the Pyeongchang Winter Olympics in the Republic of Korea, Seoul's Ministry of Unification said on Wednesday.
Also on Wednesday, Beijing criticized a foreign minsters' meeting hosted on Tuesday by Canada and the United States in Vancouver to urge the global community to maximize pressure on the DPRK.
Without engaging China, Russia and the Democratic People's Republic of Korea, the meeting on Tuesday included only officials from countries that were members of the United Nations Command that supported Seoul during the 1950-53 Korean War.
Foreign Ministry spokesman Lu Kang said the meeting hosted in the name of the UN Command "apparently reflects Cold War thinking" and only adds rifts in the global community and undermines joint efforts to settle things.
Some major parties involved were not at the table, and the main pathways for settling the issue should be the UN Security Council and the Six-Party Talks, Lu said.
All the parties should support Pyongyang and Seoul's efforts to improve ties and do more to facilitate dialogue, Lu said, adding that excessive pressure and isolation only backfires.
Zhang Liangui, an expert on Korean studies at the Party School of the Central Committee of the Communist Party of China, said recent developments show that pressuring Pyongyang is still at the top of Washington's agenda on the peninsula issue. The latest interactions between Pyongyang and Seoul have made Washington feel uneasy, Zhang said.
Russian Foreign Minister Sergei Lavrov said on Monday that the US and its allies "still want to do business solely on the basis of issuing ultimatums".