China urged the United States to immediately stop its "unsafe, unprofessional and unfriendly dangerous military activity" after a US Navy surveillance plane flew in airspace over the East China Sea on Sunday.
"China's Air Force dealt with it in accordance with laws and regulations.
"The Chinese pilots' maneuvers are legal, necessary and professional," Defence Ministry spokesman Ren Guoqiang said in a statement on Tuesday.
According to media reports, Pentagon spokesman Captain Jeff Davis said on Monday that two Chinese J-10 fighter jets intercepted a US EP-3 plane over the East China Sea during the weekend, with one jet coming within about 90 meters of the US aircraft.
Reuters cited a US official as saying that the Chinese jet was armed and the interception took place 80 nautical miles, or about 148 km, from Qingdao, Shandong province.
Ren said the US military aircraft's surveillance activities threatened China's national security, damaged both countries' military security and posed a danger to the safety of both the Chinese and US pilots.
"These actions are the root cause of the security issue between China and the US, both in the air and at sea," he said,
"The US should immediately cease such kinds of unsafe, unprofessional and unfriendly, dangerous military activity."
Foreign Ministry spokesman Lu Kang also said on Tuesday that US warships and warplanes over a period of time have carried out long-term and frequent surveillance activities near China's coast.
"Such activities seriously threaten China's maritime and air security. We urge the US to immediately stop such surveillance activity and prevent such incidents from happening again," he told reporters at a daily news conference.
Lu also said China has been devoted to safeguarding flight order and security at sea as they apply to international laws and related rules.
"We are also actively working to establish military mutual trust with other countries in order to appropriately manage and control disputes," he added.
On May 17, a US WC-135 Constant Phoenix reconnaissance aircraft carried out operations in airspace over the Yellow Sea and Chinese aircraft acted to identify and investigate in accordance with the law.
Major General Ma Gang, a professor at the PLA National Defence University, said the "countless" surveillance activities in recent years reflect that some people in the US cannot take a correct view of China's development, especially in terms of military power.
"China has to take just and professional actions when warnings do not work anymore," he said.