US, Japanese, Indian, and Philippine warships carried out drills in the South China Sea during the first week of May.

Similar exercises have been conducted in the past, but the joint effort is a fresh signal to Beijing, which has claimed a vast swath of the sea.

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TOKYO (Reuters) - In fresh show of naval force in the contested South China Sea, a US guided-missile destroyer conducted drills with a Japanese aircraft carrier, two Indian naval ships and a Philippine patrol vessel in the waterway claimed by China, the US Navy said on Thursday.

While similar exercises have been held in the South China Sea in the past, the combined display by four countries represents a fresh challenge to Beijing as US President Donald Trump threatens to hike tariffs on $200 billion worth of Chinese goods.

"Professional engagements with our allies, partners and friends in the region are opportunities to build upon our existing, strong relationships," Commander Andrew J. Klug, the captain of the US destroyer, the USS William P. Lawrence, said in a statement.