UNITED NATIONS -  The United States sounded a global call to confront the North Korean nuclear threat Friday, exhorting Beijing to use its “unique” leverage to rein in Pyongyang and avert “catastrophic consequences.”

Addressing the UN Security Council after Donald Trump warned of the risk of a “major conflict,” Secretary of State Rex Tillerson called for a campaign of pressure to force Pyongyang to change course and put a halt to its nuclear and ballistic missile programs.

“Failing to act now on the most pressing security issue in the world may bring catastrophic consequences,” Tillerson told the Council. “The threat of a North Korean nuclear attack on Seoul or Tokyo is real, and it is likely only a matter of time before North Korea develops the capability to strike the US mainland,” he said.

Tillerson told the Council there was “no reason” to think North Korea would change course under the current multilateral sanctions regime, warning: “The time has come for all of us to put new pressure on North Korea to abandon its dangerous path.” “I urge this council to act before North Korea does,” he said.

The ministerial meeting comes after US President Donald Trump told Reuters on Thursday that a “major, major conflict” with North Korea was possible over its nuclear and ballistic missile programs.

Washington has repeatedly called for tougher UN sanctions, but wants China to take the diplomatic lead by using its leverage over Pyongyang - which Beijing has been reluctant to do for fear of destabilizing North Korea. At the council meeting, China pushed back, saying it was not realistic to expect one country to be responsible for solving the conflict.

“China is not a focal point of the problem on the peninsula and the key to solving the nuclear issue on the peninsula does not lie in the hands of the Chinese side,” Foreign Minister Wang Yi said. “All options for responding to future provocation must remain on the table,” Tillerson said. “Diplomatic and financial levers of power will be backed up by willingness to counteract North Korean aggression with military action, if necessary.”

Russia and China made clear that a military response to the threat from Pyongyang would be disastrous and appealed for a return to talks and de-escalation.

China’s Wang warned “the use of force does not solve differences and will only lead to bigger disasters.”

Russia on Friday warned at the United Nations that military options to address the threat from North Korea’s nuclear and ballistic programs were “completely unacceptable” and would have “catastrophic consequences.” Russian Deputy Foreign Minister Gennady Gatilov told the Security Council that China’s proposals to re-start talks with North Korea should be seriously examined and that sanctions alone would not work.

North Korea “is conducting itself in an inappropriate way,” Gatilov told the council. “At the same time, options of using force are completely unacceptable and could lead to catastrophic consequences.”

The US chief diplomat placed the onus squarely on China - which accounts for 90 percent of North Korea’s trade - saying it “has economic leverage over Pyongyang that is unique” and suggesting sanctions from Beijing would have a strong impact.

China and Russia argued that sanctions alone were not the answer. The Chinese foreign minister pushed Beijing’s proposal for reviving talks based on a freeze of North Korea’s military programs. He said the long-standing proposal, which involves Pyongyang freezing military programs in exchange for a halt to US-South Korean annual military drills, was “reasonable and practical.”  “Now is the time to seriously consider talks,” said Wang.

The United States has rejected the Chinese proposal and insists that North Korea first take steps to show that it is ready to abandon its military programs.

Meanwhile, Seoul on Friday brushed aside US President Donald Trump’s suggestion it should pay for a $1 billion missile defence system the two allies are installing in South Korea to guard against threats from the North.

The first parts of the Terminal High Altitude Area Defense (THAAD) system have already been delivered to a former golf course in the South - infuriating China - at a time of heightened tensions over Pyongyang’s nuclear and missile programmes.

Top US officials have said THAAD will be operational “within days”.

“I informed South Korea it would be appropriate if they paid. It’s a billion-dollar system,” Trump was quoted as saying by the Reuters news agency. “It’s phenomenal, shoots missiles right out of the sky.”

The two countries have been in a security alliance since the 1950-53 Korean war, and more than 28,000 US troops are stationed in the South.

Seoul retorted that under the Status of Forces Agreement that governs the US military presence in the country, the South would provide the THAAD site and infrastructure while the US would pay to deploy and operate it.

“There is no change to this basic position,” South Korea’s defence ministry said in a statement.

The row comes with tensions high on the Korean peninsula following a series of missile launches by the North and warnings from the Trump administration that military action was an “option on the table”.

Trump said there was “a chance” of “a major, major conflict” with the North - which would put the South, whose capital is within range of Pyongyang’s artillery, at risk of horrific casualties.

But earlier this week Washington said it would seek stronger sanctions against Pyongyang and held open the possibility of negotiations, with US Pacific Command chief Admiral Harry Harris saying it wanted to bring leader Kim Jong-Un “to his senses, not to his knees”.

The White House also wants China to do more to rein in the North, with Trump saying he believed leader Xi Jinping was “trying very hard”.

Chinese foreign ministry spokesman Geng Shuang told reporters that the two presidents had been “in constant touch with each other”, which was “good for the two countries and also for the whole world”.

But Beijing has been infuriated by the THAAD deployment, which it fears weakens its own ballistic capabilities and says upsets the regional security balance.