Mr. Bush also said the United States would oppose the development of treaties or other restrictions that seek to prohibit or limit U.S. access to or use of space.
The provisions were contained in the first revision of U.S. space policy in nearly 10 years. Mr. Bush's order, signed more than a month ago, was not publicly announced, although unclassified details of his decision were posted on the Web site of the Office of Science and Technology Policy.
"Freedom of action in space is as important to the United States as air power and sea power," the policy says. "In order to increase knowledge, discovery, economic prosperity, and to enhance the national security, the United States must have robust, effective, and efficient space capabilities."
The policy says that space systems should have rights of passage without interference, and that the United States would view any deliberate interference with its space systems as an infringement on its rights.
"The United States considers space capabilities — including the ground and space segments and supporting links — vital to its national interests," the policy said.
"Consistent with this policy, the United States will: preserve its rights, capabilities, and freedom of action in space; dissuade or deter others from either impeding those rights or developing capabilities intended to do so; take those actions necessary to protect its space capabilities; respond to interference; and deny, if necessary, adversaries the use of space capabilities hostile to U.S. national interests."
"This policy emphasizes that the United States is committed to peaceful uses of space by all nations and that space systems enjoy the right of free passage," National Security Council spokesman Frederick Jones said.
He said the United States maintains the right of self-defense and the protection of its interests and assets in space.
"Protection of space assets does not imply some sort of forceful action," he said. "There is a broad range of ways to protect our space capabilities" such as system hardening, encryption, maneuvering and other methods.
"The new policy is consistent with previous national space policies in this regard," he said.
Jones said the challenges and threats facing the United States have changed in the decade since the space policy was last updated.
"Technology advances have increased the importance of and use of space," he said. "Now, we depend on space capabilities for things like ATMs, personal navigation, package tracking, radio services, and cell phone use."
The new policy was first reported by The Washington Post.