In an interview with an American news agency, North Korea's deputy foreign minister blamed U-S President Donald Trump's aggressive stance for the current crisis.
Some media report that aerial pictures of the mountainous North Korean nuclear site show it ready for a sixth test.
President Trump tweeted this week that he had great confidence that China would "properly deal with North Korea" and "if they are unable to do so, the U-S with its allies, will".
The North Korean deputy foreign minister said that Mr Trump's tweets were aggressive.
He indicated they wouldn't deter Kim Jong-un if the North Korean leader decided to hold another nuclear test.
China is urging restraint.
A conflict over North Korea could break out 'at any moment', China's foreign minister Wang Yi said on Friday, warning there would be 'no winner' in any war, as tensions soar with the US.
