China warns against Asia troublemakers China's President Xi Jinping has said no country should be allowed to throw Asia into chaos, following weeks of escalating tensions on the Korean peninsula and threats from the nuclear-armed North Korea of an imminent attack on the US and its allies. Mr Xi issued the veiled rebuke of China's North Korean ally in a speech on Sunday at a Chinese business forum attended by dozens of national leaders from Asia, Africa and Europe. "No one should be allowed to throw a region, or even the whole world, into chaos for selfish gains," he said, without naming any specific country. Countries, whether big or small, strong or weak, rich or poor, should all contribute their share in maintaining and enhancing peace. The comments hint at growing frustration in Beijing over Pyongyang's sabre-rattling and weeks of heated rhetoric. It also comes after a US defence official told Reuters Washington had decided to delay a long-planned missile test scheduled for next week "to avoid any misperception or miscalculation," given tensions with North Korea. Western diplomats attending the conference on Sunday said Mr Xi's intentionally ambiguous wording appeared to be a veiled warning to Pyongyang not to push things too far but could also have been partly directed at Washington, which is often accused by Chinese leaders of meddling in the region. The US and other countries in Asia have called on China, North Korea's only real ally, to do more to rein in the hermit kingdom and its volatile young leader, Kim Jong-eun. Australian prime minister Julia Gillard, in her speech on Sunday at the conference in Bo'ao in southern China, raised the issue of North Korea. "Any aggression [on the Korean Peninsula] is a threat to the interests of every country in the region," she said. For this reason, I do welcome the growing co-operation of all regional governments to prevent conflict on the Korean Peninsula and to counter North Korean aggression. New Zealand's prime minister John Key was also expected to urge China to use its influence to restrain Pyongyang when he met Mr Xi on Sunday in Bo'ao. China's Foreign Ministry said on Sunday it had asked Pyongyang to ensure the safety of Chinese citizens, diplomats and investments in the country but that its embassy in North Korea was operating normally. "Tensions on the Korean peninsula are rising unceasingly and China expresses grave concern about this," the ministry said in a statement. North Korean authorities have told diplomatic missions in the country they should consider leaving and that their safety cannot be guaranteed after next Wednesday. In recent days they have also stated that nuclear war is now inevitable but by Sunday there was no sign that any country had serious plans to remove its diplomats from Pyongyang. Most countries assume the strident rhetoric is a reflection of domestic politics and part of attempts by the young leader, who took over the country after his father's death in December 2011, to solidify his control over the military and bureaucracy. Mr Xi's warning came on a day when China announced it would take cruises to disputed islands in the South China Sea - a move which is in itself likely to provoke the ire of nations with rival claims to the oil rich waters. In a reflection of China's growing economic and political clout, the Bo'ao forum was attended by an unprecedented line-up of world leaders including the presidents or prime ministers of Kazakhstan, Myanmar, Peru, Zambia, Mexico, Cambodia and Finland, and by the Sultan of Brunei. During his speech on Sunday, Mr Xi stressed China's economic attractions, predicting that within five years the country's imports would reach $10tn while outbound investment would exceed $500bn. He also said the number of Chinese tourists going abroad would exceed 400m.