China expressed its "firm opposition" to erstwhile ally North Korea's latest nuclear test Tuesday and called for new denuclearization talks.

The statement from the Foreign Ministry reflects Beijing's growing frustration with its communist neighbor's provocative behavior, as well as its reluctance to impose more severe measures that could destabilize the North's hardline regime.

"The Democratic People's Republic of Korea, heedless of widespread international opposition, has again carried out a nuclear test, to which the Chinese government expresses its firm opposition," the statement said, referring to North Korea by its official name.

The statement said China maintained its resolute stance of advocating a nuclear-free Korean Peninsula, opposition to nuclear proliferation, and support for the maintenance of stability on the peninsula. It called on North Korea to abide by its denuclearization pledge, and not to "take additional actions that could cause the situation to further deteriorate."

The statement did not point to any specific actions Beijing would take in response to the nuclear test, the North's third. But it called on all sides to "respond calmly" and said issues should be resolved within the framework of long-stalled denuclearization talks involving North Korea, China, the U.S., South Korea, Japan and Russia.

China is the North's biggest source of aid and diplomatic support, but it issued an unusually strong reaction to Pyongyang's December rocket launch by agreeing to tightened United Nations sanctions on the country.