"I think the position of China is very clear. Considering the circumstances, we hope that all parties will exercise restraint, stop provoking one another or escalate tensions in the region," she said at a briefing.
Two US B-1 Lancer bombers were seen over the Osan Air Base south of Seoul on Tuesday morning. Their appearance was intended to be a show of force and solidarity of the United States and South Korea.
The two countries are presenting united front in light of a recent nuclear test carried out by North Korea. The test, North Korea's fifth and most powerful to date, was registered by monitoring services as having caused a moderate earthquake.