BEIJING — President Xi Jinping of China said in a speech on Saturday morning in Singapore that islands in the South China Sea “have been China’s territory since ancient times,” and that countries from outside the region should respect the need of Asian nations for a “peaceful and stable environment” so the nations could develop rapidly.  Mr. Xi’s remark about outside countries, reported by Xinhua news agency, was an obvious reference to the United States, which has loudly criticized China’s efforts to build sand islands atop submerged features in the South China Sea. Late last month, the United States sent a guided missile destroyer, the Lassen, within 12 nautical miles of Subi Reef, a natural feature submerged at high tide on which China has carried out a land reclamation project using huge piles of sand. The United States was challenging China’s claimed authority over waters around the land feature, and American officials said they would continue to regularly do such operations.  China has been feverishly piling sand onto reefs in the South China Sea for the past year, creating seven new islets in the region. It is straining geopolitical tensions that were already taut.  Then on Thursday, the American defense secretary, Ashton B. Carter, flew to the Theodore Roosevelt, an aircraft carrier that was sailing through the South China Sea, to emphasize the stabilizing presence of the United States in the region and blame China for activities in the past year that had led to rising tensions.  Mr. Xi made his speech on Saturday at the National University of Singapore hours before he had a historic meeting at the Shangri-La Hotel with President Ma Ying-jeou of Taiwan, a member of the Kuomintang, the party that the Communists militarily defeated in 1949 to seize full control of China.  “The most important issue Asian countries currently face is how to achieve sustainable and rapid development, which requires a peaceful and stable environment,” Mr. Xi said at the university. “This is the biggest common ground for the region’s states, and countries from outside the region should understand and respect that, as well as make a constructive contribution.”  Mr. Xi acknowledged that nations in Southeast Asia had been concerned about China’s actions in the South China Sea, but he said that “islands in the South China Sea have been China’s territory since ancient times, and the Chinese government must take responsibility to safeguard its territorial sovereignty and legitimate maritime interests.”  Official statements by Chinese officials on contested islands and waters in the South China Sea, where six governments have overlapping claims to territory, have increasingly emphasized the notion that the sea has belonged to China since “ancient times” and that ancestors of today’s Chinese had significant control of land there. Before arriving in Singapore, Mr. Xi visited Vietnam, where leaders of the Vietnamese Communist Party maintain regular ties with counterparts in China but also compete intensely with China over claims in the South China Sea.  The United States, the premier military power in the Pacific, has said that it does not take sides in the territorial disputes but will enforce freedom of navigation. On Saturday, Mr. Xi said, “Freedom of navigation and aviation has never been a problem and will never be a problem in the future, because first of all China is the one who most needs smooth navigation.”  Seeking to assure other Asian nations about China’s broad interests, Mr. Xi said “the idea of peaceful development is the inner gene of Chinese culture.”  “Some people have been hyping China’s threat,” Mr. Xi added. “This is either due to the ignorance of Chinese history, culture and current policy, or out of some misunderstanding and prejudice, and probably for some ulterior reasons.”  Mr. Xi emphasized that Southeast Asian nations could benefit from closer economic ties with China. Chinese officials have long clung to the idea that the desires of other countries to reap economic benefits from good relations with China will overcome any objections to China’s strategic moves involving territory and the military or in other areas.  “China wishes to integrate its development closer with that of its neighbors,” Mr. Xi said, “and China welcomes neighboring countries to take a fast and free ride with China’s development so that it can better benefit the neighborhood and allow everyone to enjoy the good life.”
In a speech in Singapore before he met the president of Taiwan, China’s president asked countries “outside the region” to respect stability in the area.