A series of territorial disputes with its neighbours will ensure China boosts defence spending when it reveals this year’s military budget ahead of the annual parliamentary sitting next week, security experts say.

After almost three decades of sharply increased military outlays, an increasingly assertive China now has the firepower to challenge rivals claiming strategically important and resource-rich territory in the East China and South China seas.

The Chinese navy, now second in size only to the U.S. fleet in terms of raw numbers, has become a genuine blue-water force and is conducting almost continuous patrols and exercises in these contested waters.

Over the past six months, China’s stand-off with Japan over a series of rocky islands in the East China Sea known as the Senkaku in Japan and Diaoyu in China has become more acrimonious.

Beijing is also in dispute with the Philippines and Vietnam, as well as Taiwan, Brunei and Malaysia, over territory in the South China Sea.

To pay for these deployments and new hardware in the pipeline, most analysts expect that this year’s budget will continue the long-term trend of double-digit percentage increases in annual spending.

“Estimates are still for steady growth,” said Ni Lexiong, a military expert at Shanghai University of Political Science and Law.

“With China’s current attitude, it’s not going to let itself get bullied by anyone.”

Alongside missions to assert sovereignty over disputed territory, the Chinese navy is also deploying naval flotillas to the Gulf of Aden and waters off Somalia as part of its contribution to UN-authorised anti-piracy operations in the Indian Ocean.