BEIJING (AFP) - China outlined plans to build a modern, high-tech army in a national defence plan published on Wednesday (July 24), as it accused Washington of undermining global strategic stability and warned against Taiwanese independence.

The first comprehensive white paper since 2012 offers insight into the world's largest army as it scrambles to catch up to America's formidable firepower as tensions deepen between the two powers.

"International strategic competition is on the rise," the document says, adding that the United States has adjusted its national security and defence strategies and adopted "unilateral policies".

The US "has provoked and intensified competition among major countries, significantly increased its defence expenditure, pushed for additional capacity in nuclear, outer space, cyber and missile defence, and undermined global strategic stability".

The plan calls for more cutting-edge technology in the People's Liberation Army (PLA) arsenal, admitting it "still lags far behind the world's leading militaries".

War is evolving towards "intelligent" combat, the national security plan says, citing a growing use of AI, big data, cloud computing and "new and high-tech military technologies based on IT".

China's defence spending is second only to the United States, and it said earlier this year it planned to raise it by 7.5 per cent in 2019, though the increase in expenditure has slowed as the economy has cooled in recent years.

The PLA has been focused on catching up with technology used by armed forces in the US and western Europe, and is reportedly building a third aircraft carrier as well as developing new generation destroyer vessels, fighter jets and ballistic missiles.

The US-China trade war is pushing Beijing to ramp up efforts to develop its own technological innovations, which would benefit the PLA, said Mr Lyle Morris, senior policy analyst at the RAND Corporation think tank.

"The PLA still lags behind the US military in most indicators of technological superiority, but is closing the gap fast," Mr Morris said.

WARNING TO SEPARATISTS

Despite the ambitious plans, the white paper insists the two-million-strong Chinese army is a "staunch force for world peace".

But within its own borders it is less sanguine, promising to "crack down" on separatists in Xinjiang and Tibet.

In Xinjiang - where China is accused of rounding up one million mostly Muslim Uighurs in internment camps - the People's Armed Police Force has assisted "in taking out 1,588 violent terrorist gangs and capturing 12,995 terrorists" since 2014.

Beijing is firmer still on the self-ruled island of Taiwan - which China views as its own territory - and makes "no promise to renounce the use of force" in bringing it back into the fold.

"China must be and will be reunited," the paper reads. "China has the firm resolve and the ability to safeguard national sovereignty... and will never allow the secession of any part of its territory by anyone."

It says Taiwan "separatists" are the biggest threat to the peaceful reunification of the country.

"The PLA will resolutely defeat anyone attempting to separate Taiwan from China," it says.

The Mainland Affairs Council, Taiwan's top policymaking body on China, slammed the white paper for making "absurd remarks".

"We firmly oppose and condemn Beijing authorities for using cross-strait issues as a pretext for military expansion and threatening to use force against Taiwan," it said in a statement.

And with pro-democracy protests raging in Hong Kong, China's defence ministry spokesman Wu Qian cited a law stipulating that the PLA could be deployed to maintain public order if requested by the city's semi-autonomous government.