China said on Thursday it wants to be good neighbours with North Korea, after the isolated country's state news agency published a rare criticism of Chinese state media commentaries calling for tougher sanctions over the North's nuclear programme.

The United States has urged China, North Korea's only major ally, to do more to rein in the North's nuclear and missile programmes, which have prompted an assertive response from the Trump administration, warning that an "era of strategic patience" is over.

A commentary carried by North Korea's KCNA news agency referred to recent commentaries in China's People's Daily and Global Times newspapers, which it said were "widely known as media speaking for the official stand of the Chinese party and government".

In Beijing, Foreign Ministry spokesman Geng Shuang said China's position was consistent and clear.

"China's position on developing friendly, good-neighbourly relations with North Korea is also consistent and clear," Geng told reporters, in response to a question about the KCNA commentary.

China was unswervingly devoted to the denuclearisation of the peninsula and maintaining peace and security and resolving the issue through talks, Geng added.

The WeChat account of the overseas edition of the People's Daily, in its reaction to the KCNA piece, said it was clear that North Korea's nuclear and missile activities were a threat to China.

"North Korea has not left the Cold War behind and does not want to, and is enmeshed in a web of its own spinning of antagonism between its enemies and itself," it said.

China has repeatedly said that while it is happy to help arrange talks, it is ultimately up to the United States and North Korea to sort out their differences.

Diplomats say Washington and Beijing are negotiating a possible stronger U.N. Security Council response - such as new sanctions - to North Korea's repeated ballistic missile launches in defiance of UN Security Council resolutions.

The KCNA commentary charged that the Chinese articles had attempted to shift the blame to Pyongyang for "deteriorated relations" between China and North Korea and U.S. deployment of strategic assets to the region.

It also accused China of "hyping up" damage caused by North Korean nuclear tests to China's three northeastern provinces.

Chinese state media calls for North Korea to dismantle its nuclear programme were "a wanton violation of the independent and legitimate rights, dignity and supreme interests" of North Korea and constituted "an undisguised threat to an honest-minded neighbouring country which has a long history and tradition of friendship", KCNA said.

The United States has sent a nuclear-powered aircraft carrier to Korean waters and a pair of strategic U.S. bombers flew training drills with South Korea and Japan in another show of strength this week.

"The reckless military provocation is pushing the situation on the Korean peninsula closer to the brink of nuclear war," KCNA said on Tuesday.

Tension on the Korean peninsula has been high for weeks, driven by concern that North Korea might conduct its sixth nuclear test, also in defiance of U.N. Security Council resolutions.