A UNITED States aircraft carrier strike group has begun patrols in the South China Sea despite a warning from China’s Foreign Ministry that Washington should not challenging its sovereignty in the disputed region.

The presence the Nimitz-class nuclear-powered aircraft carrier USS Carl Vinson comes after a considerable ‘ramping up’ of rhetoric out of the White House over ownership of the esource-rich South China Sea, through which about $US5 trillion worth of trade passes each year, and which contains valuable stocks of fish, minerals and fossil fuels.

The aircraft carrier began “routine” operations in the South China Sea overnight, according to its own social media sites.

CAT-AND-MOUSE

Strike group’s commander Rear Admiral James Kilby says that weeks of training in the Pacific had improved the group’s effectiveness and readiness.

“We are looking forward to demonstrating those capabilities while building upon existing strong relationships with our allies, partners and friends in the Indo- Asia-Pacific region,” he was quoted as saying by the Navy News Service.

China has also been increasing its own readiness.

A force of guided missile destroyers and frigates have just wrapped up several days in the South China Sea exercising their own preparedness. War games involving its own aircraft carrier have unnerved neighbours with which it has long-running territorial disputes.

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Earlier last week, a spokesman for Carrier Strike Group One (to which USS Carl Vinson belongs) said the navy did not discuss future operations of its units.

“The Carl Vinson Strike Group is on a regularly scheduled Western Pacific deployment as part of the U.S. Pacific Fleet-led initiative to extend the command and control functions of the U.S. 3rd Fleet,” he said.

“US Navy aircraft carrier strike groups have patrolled the Indo-Asia-Pacific regularly and routinely for more than 70 years,” he said.

The US last conducted a freedom of navigation exercise in the South China Sea in October last year, when the guided-missile destroyer USS Decatur passed through the Parcel Islands and waters which Beijing claims as its own.

LOOMING SHOWDOWN

Friction between the United States and China under US President Donald Trump has increased concerns that the South China Sea could become a flashpoint.

The US administration has been discussing sending more warships through the increasingly militarised man-made islands which Beijing is building to enforce its claims of ownership.

Exactly what form these freedom of navigation exercises will take depends on how close they come to the artificial islands which have been deemed illegal under international law.

If the warships close within 12 nautical mile (22km) of one of these islands, Beijing may claim a breach of its territorial waters.

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This would represent a significant escalation of tensions between the two Pacific powers.

On Wednesday, Chinese Foreign Ministry spokesman Geng Shuang told state media that tensions in the South China Sea had “stabilised”, and urged foreign nations including the U.S. to respect this.

“We urge the U.S. not to take any actions that challenge China’s sovereignty and security,” Geng said.

Brunei, Malaysia, the Philippines, Taiwan and Vietnam also claim parts of the waters that command strategic sea lanes and have rich fishing grounds, along with oil and gas deposits.

The US has criticised Beijing’s construction of man-made islands and build-up of military facilities in the sea, and expressed concern they could be used to restrict free movement.