"Ren criticized frequent close-in surveillance runs by US planes as raising the chance of accidents, saying such missions "threatened China's national security, harmed China-US sea-air military safety, endangered the safety of pilots from the two sides and were the root cause of China-US sea-air unexpected incidents. US Navy Capt. He called the Chinese pilot's move unsafe.China in 2013 declared an air defense identification zone over a partly contested portion of the East China Sea, demanding foreign aircraft declare their presence and follow Chinese orders. The US and others swiftly dismissed the zone as invalid and have largely ignored it. It wasn't clear iftook place inside the zone.Such incidents continue to occur despite an agreement between the two sides to prevent them from sparking an international crisis, as happened in April 2001 when a Chinese jet fighter collided with a US EP-3.

Source: Times of India July 25, 2017 11:03 UTC