U.S. Secretary of Defense Donald Rumsfeld says he wants to hear from Chinese leaders in Beijing what they plan to do with their fast growing military capability. On his plane en route to China for his first visit as defense secretary, Mr. Rumsfeld also said he hopes China moves toward becoming a more open society as it develops politically, economically and militarily.

Donald Rumsfeld, left, is greeted by Chinese General Xiong Guongki after arriving in Beijing, Tuesday

Secretary Rumsfeld says he really does not know China's intentions as it sharply increases its defense budget. A report issued by the U.S. Defense Department in July said the official Chinese military budget has doubled in the past five years to $30. But the report said China's real military budget could be three times that amount.

"I don't really know why they seem to be increasing," he said. :I think it's interesting that other countries wonder why they would be increasing their defense effort at the pace they are, and yet not acknowledging it. That is as interesting as the fact that it's increasing at the pace it is."

Secretary Rumsfeld says what he knows about Chinese intentions is only what analysts in Washington have concluded based on China's buildup of forces in recent years. He says it will be interesting to hear from senior Chinese leaders directly what their plans are, but he also says they may not have exactly decided yet.

"They will make decisions with respect to their national security, just like we do, and we then will know the direction they're going. But it's not something that one can predict. It'll be interesting to see what course they chart," he said.

Secretary Rumsfeld will meet with China's defense minister and president on Wednesday, and he will make the first visit by a senior U.S. official to the headquarters of the country's missile command. He also will speak with up-and-coming Communist Party officials at the party's school.

The secretary declined to say what issues he will raise with Chinese leaders, but he indicated that he may go beyond military matters, to include Chinese domestic issues.

"They have been and will be making choices as they go along, and obviously those of us in the United States and in other countries around the world, free countries, hope that the choices they make are choices toward a more open society, a more transparent societ," Secretary Rumsfeld said.

The secretary elaborated on that theme in an opinion column he wrote for Monday's Asian Wall Street Journal. In that article, he said China's leaders "likely will need to embrace more open and representative government if China is to fully achieve the political and economic benefits" its people want.

In the article, and in his comments on his plane, Secretary Rumsfeld said he wants to see U.S.-China military relations continue to improve, as they have in recent years, and that he hopes China will become "a strong and peaceful partner in the international system."

But the July U.S. Defense Department report warns that China's buildup has already changed the military balance in Asia, and improved its ability to use force against Taiwan, which the report says could make it more likely the country's leaders will decide to do so.

The United States has pledged to defend Taiwan against unprovoked attack. Beijing considers the separately governed island its territory and has threatened to use force to recapture it should the Taipei government declare independence.