China has expressed concerns over plans for the USS George Washington aircraft carrier to take part in a joint South Korea-U.S. military drill in the Yellow Sea.

The Chinese Foreign Ministry said Friday that it is concerned about reports the U.S. supercarrier will be entering the Yellow Sea for the exercises that will begin on Sunday. The ministry said it hopes related parties will work to ease tensions and to establish peace on the Korean Peninsula.

On international calls for China to exercise its influence on North Korea to halt future provocations in relation to the North's recent artillery attack on a South Korean island, the ministry only reiterated that the two Koreas should remain cool-headed.

Meanwhile, Chinese Foreign Minister Yang Jiechi hurriedly postponed a planned trip to Seoul. He was originally scheduled to visit Seoul on Friday.

Observers said Beijing apparently delayed the trip to avoid having to talk about the incident with South Korean officials and out of concerns that Yang’s visit could seem as if China supports South Korea on the recent incident.

Despite criticism from the international community over the North’s attack, China has maintained a rather vague stance on the matter.