US and Philippine fighter aircraft staged a joint patrol and training Tuesday over a disputed South China Sea shoal where Chinese fighter jets fired flares last year to drive away a Philippine aircraft, Philippine officials said. The joint patrol and air-intercept drills over the hotly disputed Scarborough Shoal off the northwestern Philippines were the first by the longtime treaty allies since US President Donald Trump took office again. Trump's America First foreign policy thrust has sparked concerns among Washington's allies in Asia about the scale and depth of US commitment to the region in his new term. His predecessor, Joe Biden, had moved to strengthen an arc of security alliances in the region to counter China's increasingly assertive actions. Two US Air Force B-1 bomber aircraft and three Philippine Air Force FA-50 fighter jets joined the brief patrol and training, which involved practising how to intercept a hostile aircraft, Philippine air force spokesperson Maria Consuel