China said Friday it will boost military spending by about seven to eight per cent this year, the smallest increase in six years, reflecting slowing economic growth and a drawdown of 300,000 troops as Beijing seeks to build a more streamlined, modern military.

Fu Ying, the spokeswoman for the National People's Congress, China's ceremonial legislature, told reporters that China needs to consider its defence needs, economic development and the country's fiscal position in drafting the defence budget.

The People's Liberation Army, being trimmed to 2 million troops from 2.3 million, will still be the world's largest standing military. It remains a major priority for China's leaders who have pushed an increasingly aggressive campaign to assert territorial claims in the South China Sea and East China Sea, raising tensions with its neighbours.

This year's budget comes as spending at all levels of government is being curbed because of a drop in the economic growth rate, which fell to a 25-year low of 7.3 per cent in 2015 and is expected to decline further this year. For most years since 2000, China posted double-digit increases in military spending, and this will be only the third time in that period with a single-digit increase, including 2010's increase of 7.5 per cent.

China provides no breakdown of its defence budget and Pentagon and global arms bodies estimate actual military spending may be anywhere from 40 to 50 per cent more, because the official budget doesn't include the costs of high-tech weapons imports, research and development, and other programs.

China says its military is strictly for defensive purposes, but takes a broad view of what constitutes threats to its core interests — including protecting maritime territory that is in dispute with neighbouring countries.

Its aggressive program of building islands on reefs and atolls in the South China Sea as part of its campaign to claim virtually the entire region has unnerved China's neighbours. Meanwhile, China continues a low-level campaign of confronting Japanese ships and aircraft near a set of contested East China Sea islands.