North Korea test-fired a ballistic missile on Saturday in apparent defiance of a concerted US push for tougher international sanctions to curb Pyongyang's nuclear weapons ambitions.
The latest launch, which South Korea said was a failure, came just hours after US Secretary of State Rex Tillerson warned the UN Security Council of "catastrophic consequences" if the international community - most notably China - failed to pressure the North into abandoning its weapons program.
Military options for dealing with the North were still "on the table", Tillerson warned in his first address to the UN body.
The launch ratchets up tensions on the Korean peninsula, with Washington and Pyongyang locked in an ever-tighter spiral of threat, counter-threat, and escalating military preparedness.
US President Donald Trump, who has warned of a "major conflict" with North Korean leader Kim Jong-Un's regime, said the latest test was a pointed snub to China – the North’s main ally and economic lifeline.
"North Korea disrespected the wishes of China & its highly respected President when it launched, though unsuccessfully, a missile today. Bad!" Trump tweeted.
The US is deploying a naval strike group led by an aircraft carrier to the Korean peninsula, and a missile-defence system called Terminal High Altitude Area Defense (THAAD) that officials say will be operational "within days".
North Korea recently conducted its biggest-ever firing drill and has threatened to "bury at sea" the US aircraft carrier, and there are signs it could be preparing for a sixth nuclear test.
South Korea’s defence ministry said it suspected Saturday's missile test had failed after a brief flight, while the US military's Pacific Command confirmed the rocket did not leave North Korean territory.
Japan has lodged a "serious protest and criticism" to the North, Chief Cabinet Secretary Yoshihide Suga told reporters after a national security council meeting.
Watch: US scolds UN on North Korea
Risk of nuclear attack 'real'
China pushed back at Tillerson's call at the UN Security Council for it to do more to rein in Pyongyang, arguing that it was unrealistic to expect one country to solve the conflict.
"The use of force does not solve differences and will only lead to bigger disasters," Chinese Foreign Minister Wang Yi said.
His country, he said, should not be "a focal point of the problem on the peninsula" and stressed that "the key to solving the nuclear issue on the peninsula does not lie in the hands of the Chinese side".
Russia joined China in saying a military response would be disastrous and appealing for a return to talks and de-escalation.
Military action was "completely unacceptable", Russian Deputy Foreign Minister Gennady Gatilov told the council, and a miscalculation could have "frightening consequences".
Watch: South Korea criticises North's 'vicious cycle'
But Tillerson argued that diplomacy had to be backed with credible muscle.
"Diplomatic and financial levers of power will be backed up by willingness to counteract North Korean aggression with military action, if necessary," he said.
"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."
China wants talks
The meeting of the top UN body on Friday laid bare major differences among key powers over the way to address the North Korea crisis.
Over the past 11 years, the Security Council has imposed six sets of sanctions on Pyongyang - two adopted last year - to significantly ramp up pressure and deny the North Korean regime the hard currency revenue needed for its military programmes.
But UN sanctions experts have repeatedly told the council the measures have had little impact because they have been poorly implemented.
Tillerson called on all countries to downgrade or sever diplomatic relations with North Korea and impose targeted sanctions on entities and individuals supporting its missile and nuclear program.
The United States is ready to impose sanctions on third countries where companies or individuals are found to have helped North Korea’s military programmes, he said.
People in Tokyo walk past a TV news report showing an image of Kim Jong Un while reporting North Korea's rocket launch. Source: AP
China instead wants Pyongyang to freeze its military programmes in exchange for a halt to US-South Korean annual drills.
"Now is the time to seriously consider talks," said Wang.
But Tillerson was blunt in saying it was up to North Korea to take the first concrete steps.
"We will not negotiate our way back to the negotiating table," he said. "We will not reward their bad behaviour with talks."
The United States, Russia and China took part in six-party talks on North Korea’s denuclearisation from 2003 to 2009, along with Japan, South Korea and Pyongyang.
