China must enhance the ability of its military to win "local wars", Premier Wen Jiabao said on Monday, as Beijing grows increasingly assertive about its territorial claims in Asia.

Beijing lays claim to large swathes of the South China Sea which are also claimed by its smaller neighbours, and must also secure supply routes and new sources of raw materials to fuel its booming economy.

Wen's made his comments at the opening of the National People's Congress (NPC), China's parliament, a day after the government announced military spending would top $100 billion in 2012 -- an 11.2 percent increase on last year.

"We will enhance the armed forces' capacity to accomplish a wide range of military tasks, the most important of which is to win local wars under information age conditions," Wen said in his "state of the nation" speech.

China's territorial disputes with countries including Japan, South Korea, the Philippines and Vietnam have grown rockier in recent years and its neighbours have accused it of behaving aggressively.

The Asian giant already has the world's largest armed forces and its defence budget has seen double-digit increases every year for much of the last decade, rattling the United States, which is forging ahead with plans to expand its own military power in Asia.

Analysts say actual defence spending is probably double the published figure, with funding for modernising the country's military not included in the budget.

China has made advances in satellite technology and cyber warfare in recent years and invested in advanced weaponry including its first aircraft carrier, a 300-metre-long (990-foot) former Soviet naval vessel that had its first sea trial in August.

But it remains technologically far behind the United States. Wen said Beijing aimed to "enhance our capacity for making innovations in defence-related science and technology and in weapons and equipment development".

"We will vigorously carry out military training under information-age conditions," he told the 3,000 delegates gathered in Beijing's Great Hall of the People.

China began revamping its People's Liberation Army -- the former ragtag peasant force formed in 1927 by the Communist Party -- in earnest after a difficult 1979 incursion into Vietnam, when the neighbours vied for influence over Southeast Asia.

Besides conventional weaponry upgrades, the push also led to China's fast-growing space programme and the test of a satellite-destroying weapon in 2007.

China lays claim to essentially all of the South China Sea, where its professed ownership of the Spratly archipelago overlaps with claims by Vietnam, the Philippines, Taiwan, Brunei and Malaysia.

Beijing and Tokyo also have a long-standing dispute over an uninhabited but strategically coveted island chain known as Senkaku in Japanese and Diaoyu in Chinese, which lies between Japan and Taiwan in the East China Sea.

Wen also said China will "modernise the armed police force" -- responsible for domestic security -- amid growing social unrest in Tibetan-inhabited regions and in Xinjiang, home to the mainly Muslim Uighurs.