China berthed its first aircraft carrier Sunday, its latest attempt to flex of its military muscles, AFP reports.

The 300-meter (990-foot) former Soviet carrier called the Varyag was handed over to the People’s Liberation Army at Dalian port, northeast China, state press reported. The carrier’s stern was adorned in the navy’s colors while the Chinese national flag was raised on its mast and the PLA flag was put up on its bow. The secretive Chinese military released a paper stating that the carrier, currently known only as “Number 16”, would be put into active service “sometime in the future”.

China reportedly bought the carrier’s hull – with no engine, electrics or propeller – from Ukraine in 1998 and refitted in Dalian in 2002. The United States and Japan were suspicious of the real purpose of the aircraft carrier since it conducted several sea trials last year. Beijing claimed that the carrier “poses no threat to its neighbors and will be used mainly for training and research purposes,” AFP reports.

This comes amid the mounting tensions in the region over China’s territorial disputes with its neighbors. Pentagon accused Beijing of lacking transparency about its defense programmes and spends between $120 to $180 billion on its military.