US destroyer in South China Sea
US Navy's guided-missile destroyer sails through the South China Sea near artificially made islands which are unilaterally claimed by BeijingUS Navy handout via Reuters

The US has pledged to undertake more naval patrols in the South China Sea despite China's stinging rebuke. The US determination came after China summoned the American ambassador to Beijing to express its disapproval of the manoeuvres by the guided-missile destroyer USS Lassen.

US Defence Secretary Ash Carter showed no hesitation during a congressional hearing insisting that the US warship remained in international waters. Responding to lawmakers who warned the US was risking its credibility over the tensions, Carter said: "We will fly, sail and operate wherever international law permits. There have been naval operations in that region in recent days and there will be more in the weeks and months to come."

USS Lassen sailed within 12 nautical miles (22.2km) of Subi and Mischief reefs in the Spratly Islands, the transit mission lasting a few hours. The region is widely considered as international waters but Beijing claims large parts of the South China Sea. Many nations including Vietnam, Taiwan, the Philippines and Malaysia are entangled in messy territorial claims in the region.

Subsequent to the American warship's foray into the area, high-profile Chinese authorities have been issuing sharp warnings to the US to not escalate tensions. Lu Kang, a spokesperson of the Chinese ministry of foreign affairs, said: "If any country thinks that, through some gimmicks, they will be able to interfere with or even prevent China from engaging in reasonable, legitimate and legal activities in its own territories, I want to suggest those countries give up such fantasy.

"In fact, if relevant parties insist on creating tensions in the region and making trouble out of nothing, it may force China to draw the conclusion that we need to strengthen and hasten the buildup of our relevant capabilities. I advise the US not to create such a self-fulfilling prophecy."

When asked whether China would consider responding militarily to the situation, Lu sidestepped the question saying: "I will not answer hypothetical questions. We hope that the US side will not take actions that will backfire."