WASHINGTON: Two US bombers flew over the disputed South China Sea, the US Air Force said in a statement on Friday, asserting the right to treat the region as international territory, despite China’s territorial claims in the busy waterway.

Before their flight on Thursday, the two B-1Bs trained with Japanese jet fighters in the neighboring East China Sea, the first time the two forces have ever conducted night-time drills.

That US military activity came amid heightened tension in the region after North Korea claimed it has developed a long range missile that could threaten the United States.

The US wants China to do more to pressure Pyongyang to halt its research into missiles and nuclear bombs.