North Korea threatens weekly missile tests as crisis escalates
North Korea has vowed to continue regular nuclear weapons testing and warned of "all-out war" if the United States takes military action.
Pyongyang carried out a failed missile launch on Sunday in a provocative move that ramped up tensions with Washington.
North Korea's vice foreign minister Han Song-Ryol said the rogue state would react with a pre-emptive strike in the face of American force.
He told the BBC: "We'll be conducting more missile tests on a weekly, monthly and yearly basis."
Warning of "all-out war" if the US takes military action, he added: " If the US is planning a military attack against us, we will react with a nuclear pre-emptive strike by our own style and method."
US President Donald Trump told North Korea it "gotta behave" when he answered questions from a reporter in the White House as the crisis escalated.
Vice-president Mike Pence, meanwhile, said the "era of strategic patience is over" during a visit to Seoul and he told South Korea the US is with the nation 100%.
"President Trump has made it clear that the patience of the United States and our allies in this region has run out and we want to see change," he said.
"We want to see North Korea abandon its reckless path of the development of nuclear weapons, and also its continual use and testing of ballistic missiles is unacceptable."
He warned Pyongyang "would do well not to test" the resolve of Mr Trump.
The UK has urged North Korean leader Kim Jong-un to stop "these belligerent acts and comply with UN resolutions", but No 10 refused to be drawn on reports that Prime Minister Theresa May has privately urged Mr Trump not to launch air strikes on North Korea.
Russian foreign minister Sergey Lavrov warned the US against "unilateral actions like those we saw recently in Syria" and urged the US to "follow the line that president Trump repeatedly voiced during the election campaign".
Mr Trump has ordered aircraft carrier USS Carl Vinson and several warships to the area to highlight American concern at the situation, as China expressed fears war could erupt "at any moment".