The file photo shows a J-20 stealth fighter jet attached to the Chinese PLA Air Force flies through the clouds overhead during a flight training exercise. (eng.chinamil.com.cn/Photo by Yang Jun)

An ace test pilot of China's J-20 stealth fighter jet recently revealed that the J-20 is receiving constant upgrades, and a next generation warplane is expected to make its debut soon.

"The J-20 is constantly improving, keeping pace with the times, and continuously perfecting its mission system to achieve its expected combat objectives," said Li Gang, the test pilot in the J-20's maiden flight, China Central Television (CCTV) reported on Wednesday.

Since the J-20's first test flight in 2011, China's aviation technologies have developed at an astonishing speed, far surpassing that of other countries, Fu Qianshao, Chinese military aviation expert, told the Global Times on Thursday.

The latest technologies have been applied to the J-20, including aerodynamic design changes and new engines, as well as the avionics, radar systems, software and materials, Fu said.

With these upgrades, the J-20 is now the world leader by far in advanced fighter jets, Fu said, noting that the US' F-22 has not received any major upgrades since its development, and its technologies are becoming obsolete.

But China will not sit on the J-20, with countries like the US having already started developing sixth-generation fighter jets, observers said.

"As the technology of our country's aviation industry continues to develop, the next generation will definitely come out soon," CCTV quoted Li, the J-20 test pilot, as saying.

China trailed behind the US at the start of the J-20's development, but now for the next generation fighter jet, China has either caught up with the US or is leading the world, Fu said.

The new warplane will likely also be built with an open architecture that allows fast development, fast production and fast upgrades like the J-20, analysts said.

No additional information has been given for China's next-generation fighter jet. Observers noted that some global trends include the integration of artificial intelligence, loyal wingman drones, more advanced engines that lead to faster speeds, stronger situational awareness, higher stealth capability, as well as the assumption of the role of a C4ISR (command, control, communications, computers, intelligence, surveillance and reconnaissance) node.