BEIJING (Reuters) - China has set up a tsunami alert center in the South China Sea, the head of the country’s maritime regulator said on Wednesday, in Beijing’s latest effort to bolster its jurisdiction in the disputed waters.

China claims most of the energy-rich waters through which about $5 trillion in ship-borne trade passes every year. Neighbors Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims.

The United States has voiced concerns about China’s assertive pursuit of territory in one of the world’s busiest trade routes.

The tsunami alert center is under construction but has already begun initial operations, Wang Hong, the chief of the State Oceanic Administration told reporters on the sidelines of China’s annual meeting of parliament.

“We have already begun issuing tsunami alerts to the international community, including countries on the periphery of the South China Sea,” Wang said.

“Cooperation in the South China Sea is one of our important focuses. We hope to collaborate with South China Sea countries and create a peaceful and harmonious sea,” Wang said.

He did not give details on the center’s location.

China’s increasingly assertive claims in the South China Sea, along with its rapidly modernizing navy, have rattled nerves around the region.

Beijing has said that its operations in the sea, including land reclamation work on disputed reefs and islands, are largely intended to bolster civilian research, search and rescue and maritime security and will benefit other countries.

Nonetheless, China says it is entitled to “limited defensive facilities” on its territory. It has dismissed reports about surface-to-air missiles placed on the disputed Woody Island as media hype.

The U.S. military, which remains by far the most powerful naval force in the region, has warned that Beijing is seeking to establish a level of de facto control over the South China Sea that threatens freedom of navigation for international shipping.