The jet is China’s somewhat secretive answer to rivals such as Lockheed Martin’s F-22 Raptor, which was developed for the U.S. Air Force. The country held a maiden test flight for the prototype of the J-20, its first stealth fighter, in 2011, surprising experts with the progress it had already made.

Like the F-22, the J-20 is a so-called fifth-generation fighter that boasts stealth technology and can cruise at supersonic speeds.

Earlier this month, China’s air force started training a new generation of pilots for the J-20. Now, according to a brief article from the state media organization Xinhua, the jet has been “officially commissioned into military service.”

When China showed off the production model of the J-20 in public for the first time in late 2016, some were surprised that it was doing so before putting the jet into service. This, observers suggested, showed a lot of confidence in the fighter. It is likely also symptomatic of China’s current assertiveness in the region.

The announcement that the J-20 is now in service comes weeks before a crucial conference of China’s Communist Party.

One interesting piece of information about the J-20 that emerged this month was the fact that China is building its own engines for the stealth fighter. This is important because current production models use a Russian engine—in future, China won’t have to rely on a foreign supplier for that crucial part.

U.S. lawmakers have previously alleged that China stole American technology—specifically, that used in Lockheed Martin’s F-22 Raptor—to develop the J-20.