South Korea says China is taking a firmer position on North Korea lately, suggesting Beijing may view North Korea increasingly as a liability rather than an asset.

Foreign Ministry spokesman Cho June-hyuck told reporters Tuesday that a recent series of strong messages from Beijing is a stern warning to Pyongyang that is posing grave threat to the Korean Peninsula with illegal nuclear and missile development.

The Global Times, an English-language daily controlled by the Chinese Communist Party, warned that if North Korea conducts a sixth nuclear test, China could sharply slash oil supplies to the North.

The Chinese Foreign Ministry on Monday strongly urged related countries to remain calm and cool-headed and to avoid acts that escalate tensions in the region.