US Ambassador to the UN Nikki Haley (right) speaks with her Chinese counterpart Liu Jieyi before a UN Security Council meeting over North Korea, on September 4. ? AFP

United Nations, US: China on Monday again urged diplomatic talks to address the crisis with North Korea and warned at the UN Security Council that it will not allow chaos and war on the Korean peninsula.

"The situation on the peninsula is deteriorating constantly as we speak, falling into a vicious circle," said Chinese Ambassador Liu Jieyi.

"The peninsula issue must be resolved peacefully. China will never allow chaos and war on the peninsula."

His appeal was echoed by Russia, which said that diplomatic negotiations were the only way to settle the crisis over North Korea´s nuclear and missile programs.

Russian Ambassador Vassily Nebenzia said there was "an urgent need to maintain a cool head and refrain from any action that could further escalate tensions."

Russia backs China´s proposal for a freeze on North Korea´s nuclear and missile tests in exchange for a suspension of US-South Korea military drills.

US Ambassador Nikki Haley however rejected the proposal as "insulting" and said it was time to ratchet up the pressure on North Korea by enacting the "strongest possible measures."

"When a rogue regime has a nuclear weapon and an ICBM pointed at you, you do not take steps to lower your guard. No one would do that. We certainly won´t," she declared.

Russia and China did not specify whether they would support additional sanctions on North Korea.

The United States, Britain, France, Japan and South Korea requested the urgent meeting after North Korea detonated what it described as a hydrogen bomb designed for a long-range missile.

South Korea´s defense ministry warned Monday that Pyongyang may be preparing another missile launch after two tests in July of intercontinental ballistic missiles (ICBMs) that apparently brought the US mainland into range.