All sides concerned should work ­together to bring the Korean nuclear ­issues to the negotiating table, Chinese foreign ministry spokesperson Hong Lei said on Tuesday.

It is imperative that dialogue and negotiations are resumed to promote denuclearization of the Korean Peninsula, and to safeguard peace and stability in Northeast Asia, Hong told a daily news ­briefing Tuesday.

Hong's remarks came in response to mounting calls for tougher sanctions on North Korea following its announcement last week that it had carried out a successful hydrogen bomb test.

The test, if confirmed, is the fourth nuclear test conducted by North Korea. The previous three were carried out in 2006, 2009 and 2013.

China "firmly opposes" the nuclear test, the foreign ministry said.

The objective of ­denuclearization of the Korean Peninsula and the ­international nuclear non-proliferation regime should be upheld, Hong said, adding that peace and stability in the ­region must be maintained.

North Korea said on Tuesday the ­nuclear test was not intended to be a provocation or threat.

A lengthy commentary by the ­official Korean Central News Agency (KCNA) underlined the North's claim that the ­nuclear test was of a powerful ­miniaturized hydrogen bomb which marked a "new high stage" in the ­country's search for a credible nuclear deterrent.

Experts have largely dismissed the claim, saying the test yield was far too low for a full-fledged thermonuclear device and was similar to the simple fission implosion devices it has tested three times in the past.

The KCNA commentary said the test was an indispensable stage on the "­normal course" which other countries have taken to the development of a two-stage fission-fusion H-bomb.