WASHINGTON ( CNN ) -- The Chinese military continues to increase spending on efforts to break into U.S. military computer systems , expand its Navy , and invest in intercontinental nuclear missiles and weapons to destroy satellites , according to the latest U.S report on China 's military power . Chinese military officers after a meeting about the People 's Liberation Army in 2007 . The annual report from the Pentagon to Congress says China 's total military spending in 2007 was between $ 97 billion and $ 139 billion , but it is hard to tell exactly how much was spent and on what . In comparison , the U.S. military budget request for 2008 is $ 481.4 billion , not including war requests . Pentagon officials said a chunk of China 's spending went to cyberwarfare , because 2007 saw several `` intrusions '' believed to be from the Peoples Liberation Army . In the incidents , unclassified U.S. military computer systems were broken into and information was taken , according to Pentagon officials . While the information taken was not classified , Pentagon officials said the worry is the Chinese hacking required many of the skills and capabilities that would also be required for a computer network attack . Last summer , a cyber-attack on Department of Defense computer systems took down the e-mail capability of hundreds of staffers for weeks , but the Pentagon still will not comment on who initiated the attack . It is widely believed among the military to have been the Peoples Liberation Army . China is also investing heavily in and fielding improved nuclear intercontinental ballistic missiles and antisatellite missiles , according to the report . The United States expressed its concern last year after China fired a missile at one of its old satellites and destroyed it , sending thousands of dangerous pieces of space debris into orbit . The United States conducted a similar strike last month on a broken U.S. spy satellite before it re-entered the Earth 's atmosphere . U.S. officials said the satellite was hit and broke into thousands of small pieces that burned up as they re-entered Earth 's atmosphere . The United States is also concerned about the purchase of more submarines by the Chinese navy as well as plans for more aircraft carriers . The Chinese once had a small Navy . Now the United States is keeping an eye on the growing service amid concerns over Taiwan . The concerns include `` China 's near-term focus on preparing for contingencies in the Taiwan Strait , including the possibility of U.S. intervention , which is an important driver of its modernization , '' the report says . Additionally , the Chinese have placed about 100 more short-range missiles on the shore opposite Taiwan in the past year , it says . Pentagon officials worry the continued increase in Chinese military spending is slowly tipping the balance of power between China and Taiwan in China 's favor . The United States has said it would help defend Taiwan if China invaded . The report also says the Peoples Liberation Army is `` pursuing comprehensive transformation from a mass army designed for protracted wars of attrition on its territory to one capable of fighting and winning short-duration , high-intensity conflicts along its periphery against high-tech adversaries . '' Such an army , the report says , would have `` the greatest potential to compete militarily with the United States and field disruptive military technologies that could , over time , offset traditional U.S. military advantages . '' The United States says the lack of transparency by the Chinese on its spending poses `` risks to stability by increasing the potential for misunderstanding and miscalculation , '' and that China has yet to explain to the international community the purpose of its military expansion , Pentagon officials said . E-mail to a friend .
Pentagon : Chinese military expanding its Navy , investing in weapons . Officials worry China is trying to hack into U.S. military computers . `` Intrusions '' have already happened , officials say , though info was not classified . Pentagon : China 's lack of transparency makes it hard to know the extent of activity .