Beijing,  China has reportedly warned the United States to stop surveillance by patrol aircrafts near its territory if it wants to repair the damaged bilateral ties. Speaking at a press conference on Thursday, Yang Yujun, spokesman for the Ministry of National Defense, denied US State Department’s claim that the U.S. had notified China in advance about the surveillance flights and that the operation was “open and transparent,” reported China Daily. Yujun said that China never received any notification from the U.S. every time they sent a reconnaissance flight. The report quoted Chinese military officials as saying that Washington has conducted 500 surveillance operations every year. Zhang Junshe, deputy director of China”s Naval Military Studies Research Institute, pointed out that the U.S. spy flights pose a significant threat to security because they often take a route that is close to China”s territorial waters, about 12 nautical miles from the coastline. A Chinese J-11, a Russian design Su-27, had recently intercepted a U.S. Navy P-8 aircraft on August 19 while the flight was conducting a reconnaissance mission about 220 km from Hainan Island. The incident served as a reminder of the collision between a Chinese PLA navy J-8 fighter jet and a US Navy EP-3 spy plane on April 1, 2001 that killed Chinese pilot, Wang Wei, the report said.