Two Chinese fighter jets carried out an "unsafe" intercept of a U.S. military reconnaissance aircraft over the South China Sea, the Pentagon said in a statement on Wednesday. The incident is viewed as a further escalation of tensions in and around the contested waterway. The intercept comes days before President Barack Obama travels to parts of Asia from May 21-28, which will include a Group of Seven summit in Japan and his first trip to Vietnam. The incident took place in international airspace on Tuesday as the U.S. maritime patrol aircraft carried out "a routine U.S. patrol," the statement said. The incident comes a week after China scrambled fighter jets as a U.S. Navy ship sailed close to a disputed reef in the South China Sea. Another Chinese intercept took place in 2014 when a Chinese fighter pilot few acrobatic maneuvers around a U.S. spy plane.