The US Air Force has flown two B-52 strategic bombers within the vicinity of the Spratly Islands in the South China Sea, a US military official says, in a move that is expected to draw ire from China.
The flyovers on Monday came a day after US Secretary of Defense James Mattis warned Beijing against militarization of the islands.
The Pentagon chief accused China of "intimidation and coercion" in the Indo-Pacific region, asserting that the US was not going to end its military presence in the region.
Beijing lays claim over the Spratly Islands but the US and other countries surrounding the waters -- Malaysia, Vietnam, the Philippines and Taiwan – dispute that claim.
Taking advantage of the geographic features in the region, China has built several man-made islands there, equipping some of them with advanced military facilities such as anti-ship and anti-aircraft missiles.
The unnamed US military official, who was aware of the mission's original flight path, told CNN that the nuclear capable B-52 bombers flew around 20 miles from the Chinese islands.
Meanwhile, US Air Force Capt. Victoria Hight, a spokeswoman for US Pacific Air Forces, denied that the bombers had breached the Chinese airspace around the islands.
Another Pentagon spokesman claimed that the Guam-based bombers were conducting "a routine training mission" and were on their way from Andersen Air Force Base in the US Pacific territory "to the Navy Support Facility" located in the UK territory of Diego Garcia in the Indian Ocean.
Lieutenant Colonel Chris Logan said the flight was ordered by the US Pacific Command's as part of its "Continuous Bomber Presence" missions which are "intended to maintain the readiness of US forces."
Washington openly opposes China’s claim over the sea and it also constantly accuses Beijing of undertaking a land reclamation program through building artificial islands in the sea and deploying weapons there. Washington also says Beijing could use the islands as military bases.
The flyover is likely to further escalate tensions between the two sides following a recent “Freedom of Navigation” mission by two US warships, which sailed near the Chinese islands in the contested waters.