CHINA lambasted South Korea for escalating the east Asian nuclear crisis yesterday after Seoul announced further deployment of US anti-ballistic missiles.

Foreign Ministry spokesman Geng Shuang said "China is seriously concerned" after South Korean Defence Ministry said four more missile launchers will be added to the anti-missile system sited at a southern golf course.

That would bring the Terminal High-Altitude Area Defence (Thaad) system to its full strength of six launchers — against the objections of locals who fear becoming a target of North Korean nuclear weapons.

"China demands that the US and the ROK respect the security interests and concerns of China and other regional countries, with an immediate stop to the deployment process and removal of the equipment," Mr Geng insisted.

He warned Thaad — with its minimum interception altitude of 50 miles — would not defend South Korea but only undermine the regional strategic balance and raise tensions.

Seoul’s move came three days after Pyongyang conducted its most advanced nuclear test yet — a hydrogen bomb with an estimated yield of 100-150 kilotons, more powerful than the warheads on Britain’s Trident missiles.

On Tuesday the South Korean navy conducted live-fire missile launch drills in response.

Meanwhile yesterday South Korean President Moon Jae In — elected in May on the promise of detente with the north — met his Russian counterpart Vladimir Putin on the sidelines of a development summit in Vladivostok.

He urged Mr Putin to support more sanctions on Pyongyang, already under virtual blockade, including cutting off oil supplies.

On Monday Mr Moon asked Mr Putin to expel North Korean migrant workers, claiming their remittances fund the nuclear programme.

But Putin said such moves would only hurt ordinary Koreans a reiterated his call the previous day for talks under the Chinese-Russian-proposed roadmap, not confrontation.

"We should not give in to emotions and push Pyongyang into a corner," he said, adding it was “altogether impossible” t resolve the crisis without diplomacy.

South Africa’s department of Foreign Affairs also called for talks on Tuesday, saying: “As long as some states... continue to possess these Weapons of Mass Destruction, other states may always aspire to acquire similar capabilities.”

Japanese PM Shinzo Abe will meet Mr Putin today [THURS]. Before departing Tokyo yesterday, he said: "We must make North Korea understand there is no bright future for the country if it pursues the current path."