China's defence budget this year will rise about 10 percent compared with 2014, a top government official said on Wednesday, outpacing the slowing economy as the country ramps up investment in high-tech equipment such as submarines and stealth jets.
Parliament spokeswoman Fu Ying told reporters the actual figure would be released on Thursday, when the annual session of the largely rubber-stamp National People's Congress opens.
Last year, defence spending was budgeted to rise 12.2% to $130 billion, second only to the US Pentagon's proposed $534 billion base budget.
The official Xinhua news agency said the 2015 target - which would put defence outlays at around $145 billion - would represent the slowest growth in military spending in five years.
China has logged a nearly unbroken two-decade run of double-digit budget increases, though many experts think the country's real defence outlays are larger than stated.
The military build-up has rattled nerves around the region, particularly as China has taken an increasingly robust line on its territorial disputes in the East and South China Seas.
Asked about China's defence spending, Japanese Chief Cabinet Secretary Yoshihide Suga said Japan was concerned the figure "lacks transparency."
"It is true, regardless of China's defence spending, that the security situation in the region surrounding Japan is severe for various reasons," he added.
"On top of our own efforts in the field of diplomacy and defence, it is extremely important for our country to strengthen the US-Japan alliance."
The US Army's commander in Asia told Reuters China's rapidly increasing defense spending would only be a cause for alarm if Beijing used its resources to be provocative - as had happened in some parts of Asia.
General Vincent Brooks cited "bullying behaviors that happen in the sea and in the air," or "pressuring that's being done in bilateral dialogues with countries to be prepared to make a choice between the relationship with the U.S. and the relationship with China."
Other examples include "extraordinary maritime reclamation work" by China in the South China Sea, he said in an interview.
Brooks said China was investing in defense at a pace "that really no one can keep parallel with" and this showed the need for closer US interaction with Beijing's military.
India is working to narrow the military gap with China, which has unnerved New Delhi with forays into the Indian Ocean.
An Indian defence official looking at regional security issues said the double-digit rise was no surprise.
"There was some talk it could slow down in view of the economic slowdown, but our sense was modernization will remain on track," the official said.
India has announced a $40 billion defence budget for 2015-16, representing a 7.9% rise over the allocation for 2014-15. Defence analysts said it may not be enough to acquire fighter planes, submarines and warships all at once.
In addition to the Obama administration's proposed $534 billion base budget, it also wants to spend $51 billion in war funds as it urged Congress to end cuts it says erode US military power.
Fu said China faced greater challenges in modernising its military than "great powers".
"We have to rely on ourselves for most of our military equipment and research and development," Fu said. "Fundamentally speaking, China's defence policy is defensive in nature. This is clearly defined in the constitution. We will not easily change this direction and principle."
Serving and retired military officers have said pervasive graft has undermined the armed forces' prowess and morale among the rank and file, a problem robust spending may help alleviate.
Former top military officers have been among the most powerful people ensnared as Chinese President Xi Jinping has pursued corrupt officials in all walks of life.
While Beijing keeps the details of its military spending secret, experts have said additional funding would likely go towards beefing up the navy with anti-submarine ships and developing aircraft carriers beyond a sole vessel in operation.
Naval shopping list
"Carriers have definitely got to be on the list," said John Blaxland, Senior Fellow at the Strategic and Defence Studies Centre at the Australian National University in Canberra. "But also we've seen a massive surge in the number of submarines, and of course everybody loves submarines. The intimidatory effect of a submarine is hard to beat."
Money would also likely go into cyber capabilities and satellites, Blaxland added.
China's leaders have routinely sought to justify the country's military modernisation by linking defence spending to rapid GDP growth. But growth of 7.4% last year was the slowest in 24 years, and a further slowdown to around 7% is expected in 2015.
"We have achieved so much success with reform and opening up, we have not relied on gunboats to develop roads, but instead we have relied on complete and mutual beneficial cooperation," Fu said.
"We have been successful on this road, the road of peaceful development."
US military and diplomatic "rebalancing" towards Asia and Xi's crackdown on corruption in the People's Liberation Army, are among the other factors keeping military spending high, experts have said.
Beijing also says it faces a threat from Islamist militants in the far western region of Xinjiang, and is drafting an anti-terror law that will create a legal framework for sending troops abroad on counter-terrorism missions.