China expressed Saturday its "firm opposition" to a Pentagon report that said Beijing was carrying out aggressive cyber espionage as part of a steady build-up of its military power, state media said.
Foreign ministry spokesman Hong Lei said "China's justified and normal military development" had been unjustly criticised in the annual report, which was released on Friday, according to the Xinhua news agency.
The development of China's "limited" military force was only geared towards safeguarding its independence, sovereignty and territorial integrity, said the spokesman.
"So long as a country is not hostile to China, it will show no doubt or worry over such development," he added.
He told Washington to "respect facts, change its mind-set and stop its wrongdoing in issuing similar reports year after year".
Echoing recent warnings from intelligence officials, the Pentagon blamed China for "many" of the world's cyber intrusions over the past year targeting US government and commercial networks, including companies "that directly support US defense programs".
The Pentagon assessment also accused China of exploiting Western commercial technology and buying more anti-ship missiles. Washington has routinely urged Beijing to be more open about its military intentions.
The annual assessment of China's military resembled previous reports but adopted more diplomatic language, possibly to avoid aggravating delicate relations with Beijing, analysts said.
The American military has long worried that China could potentially limit the reach of US naval ships in the western Pacific with new weapons, and the Pentagon report underlined those concerns.
China's military budget officially reached $106 billion in 2012, an 11.2 percent increase.
But the US report said that budget does not include major expenditures such as improvements to nuclear forces or purchases of foreign-made weapons. Real defence spending amounts to $120 to $180 billion, the report said.
US military spending, however, still dwarfs Chinese investments, with the Pentagon's proposed budget for 2013 at more than $600 billion.
Friday's document was released as the House of Representatives voted to force the US government to sell 66 new fighter-jets to Taiwan, which Beijing considers part of China.
Taiwan welcomed the vote.
"The defence ministry is deeply grateful that the US Congress attaches much importance to Taiwan's aerial safety," it said in a statement.
"We will conduct a comprehensive evaluation of the F16 C/D fighter jets and fully negotiate with the US side to acquire the jets that will meet our aerial defence needs."
President Barack Obama's administration, anxious to keep ties with an increasingly assertive China on track, is only planning to upgrade existing planes. The measure still needs Senate approval.