US President Donald Trump has renewed sanctions on North Korea, citing an "extraordinary threat" from its nuclear weapons - just 10 days after saying there was no risk from Pyongyang.

"There is no longer a Nuclear Threat from North Korea," he tweeted on 13 June, a day after meeting the country's leader Kim Jong-un in Singapore.

The move came as the US and South Korea cancelled two more training exercises.

The Pentagon said the goal was to support diplomatic negotiations.

It follows the decision earlier this week to suspend a major joint military exercise between the US and South Korea that had been planned for August.

President Trump promised to end the annual "war games" between the allies in an unexpected concession at his summit with Mr Kim, calling them "provocative" and "expensive".

That came as a shock to many, as the US had previously argued that the drills were purely defensive and key to its military alliance with Seoul.