Washington, Jul 8 (IANS): Two US B-1 bombers flew over disputed waters in the East and South China Seas, conducting a joint military operation with Japanese fighter jets, the media reported.

The bombers were joined by two Japanese F-15 fighters on Thursday night and carried out a cooperative mission over an area both Japan and China claim as their own, US defence officials told CNN on Friday.

This mission marked the first time US B-1 bombers from the Pacific Command have carried out an operation of this kind with Japanese fighters at night, according to a statement from US Pacific Air Forces.

"Flying and training at night with our allies in a safe, effective manner is an important capability shared between the US and Japan," said Major Ryan Simpson, Pacific Air Forces chief of bomber operations.

"This is a clear demonstration of our ability to conduct seamless operations with all of our allies," he added.

The Japanese Air Self Defence Force claims that the mission was not intended to send a message to any specific country despite previous face-offs in the East China Sea with Chinese ships and warplanes.

This mission came ahead of President Donald Trump's meeting with his Chinese counterpart Xi Jinping at the ongoing G20 summit in Hamburg, Germany.

Earlier this year, US Defence Secretary James Mattis reaffirmed US commitment to defending Japan and its disputed islands, reports CNN.

The US has routinely challenged Beijing's claims to sovereignty in the South China Sea and the issue has put a strain on relations between the two powerful nations for years.

On July 2, a US Navy destroyer sailed within 12 miles of a disputed island in the South China Sea.

China called the action "a serious political and military provocation".