China's leaders issued thinly veiled rebukes to North Korea for raising regional tensions, with the president saying no country should throw the world into chaos and the foreign minister warning that Beijing would not allow mischief on its doorstep.
The comments at an economic forum on Sunday were the strongest yet by China in response to more than a month of North Korean rhetoric that has included threats to launch a nuclear attack on the United States and to wage war with Seoul.
No country "should be allowed to throw a region and even the whole world into chaos for selfish gain", President Xi Jinping told the forum in Bo'ao on the southern Chinese island of Hainan.
He did not name North Korea, but appeared to refer to Pyongyang, Reuters reports.
Former US ambassador to China Jon Huntsman said Mr Xi's comments were unprecedented.
"It suggests to me, as I've watched the ratcheting up of frustration among Chinese leaders over the last many years, that they've probably hit the 212-degree boiling point as it relates to North Korea," he told CNN.
North Korea began its latest round of threats after United Nations sanctions were imposed for its nuclear test on 12 February, the country's third.
Despite the rhetoric, Pyongyang has not taken any military action and has shown no sign of preparing its 1.2 million-strong army for war, indicating the threats are partly intended for domestic consumption to bolster young leader Kim Jong-un.
South Korean media said on Friday the North had moved two medium-range missiles to its east coast, but there has been no confirmation of such a move. The US has said it would not be surprised if the North conducted another missile test.
North Korean authorities have told diplomatic missions in Pyongyang they could not guarantee their safety from Wednesday - after saying conflict was inevitable amid joint US-South Korean military exercises due to last until the end of the month. Staff at embassies appeared to be remaining in place over the weekend.
South Korea said it was ready for any kind of action - including a possible missile launch - by Wednesday.
China, North Korea's sole financial and diplomatic backer, has shown growing irritation with Pyongyang.
Beijing negotiated the new UN sanctions with Washington and has said it wanted them implemented. The measures tighten financial curbs on North Korea, order mandatory checks of suspicious cargo and strengthen a ban on luxury goods entering the country.
"We oppose provocative words and actions from any party in the region and do not allow trouble-making on China's doorstep," Chinese Foreign Minister Wang Yi said, according to a ministry statement on its website late on Saturday, relating a telephone conversation with UN Secretary-General Ban Ki-moon.