In late May, Chinese officials told the United States to stop sending surveillance flights near land formations that China claims as its territory. American officials say the flights have been over international waters.

Admiral Sun’s remarks came during a question-and-answer session after he delivered the main Chinese speech at the annual Shangri-La Dialogue security conference in Singapore. As at previous such meetings, much of the focus of the conference, which ended on Sunday, was on territorial disputes in the South China Sea, where China, Taiwan and Southeast Asian nations all have competing claims to waters, islands, reefs, shoals and sandbars. In recent weeks, the United States has criticized China for island-building and land reclamation efforts on disputed reefs and atolls that were uninhabited until recently.

In his address to the security conference on Saturday, Ashton B. Carter, the United States defense secretary, reiterated an earlier demand for China and other nations to stop such island-building. The United States has said that China is building much faster than any other nation and has completed 2,000 acres of land reclamation in the last 18 months. Vietnam and the Philippines have built structures on some land formations, but much of that construction took place before 2002, when China and rival claimants to territory signed a nonbinding agreement to cease any provocative activity in the region.

About a month ago, the United States military spotted a pair of mobile artillery vehicles on one of the new islands, but those soon vanished, American officials said last week. China has said its islands will be used for maritime aid as well as military defense.

“China and the Chinese military have never feared the devil or an evil force, and we are convinced by reason but not by hegemony,” Admiral Sun said on Sunday, according to a transcript of his speech posted by the Chinese Defense Ministry. “Don’t ever expect us to surrender to devious heresies or a mighty power. And don’t ever expect us to swallow the bitter fruits that would harm our sovereignty, security and development interests.”