WASHINGTON - President Bush this week declared that he has the power to bypass four laws, including a prohibition against using federal funds to establish permanent US military bases in Iraq, that Congress passed as part of a new defense bill.

Bush made the assertion in a signing statement that he issued late Monday after signing the National Defense Authorization Act for 2008. In the signing statement, Bush asserted that four sections of the bill unconstitutionally infringe on his powers, and so the executive branch is not bound to obey them.

"Provisions of the act . . . purport to impose requirements that could inhibit the president's ability to carry out his constitutional obligations to take care that the laws be faithfully executed, to protect national security, to supervise the executive branch, and to execute his authority as commander in chief," Bush said. "The executive branch shall construe such provisions in a manner consistent with the constitutional authority of the President."

One section Bush targeted created a statute that forbids spending taxpayer money "to establish any military installation or base for the purpose of providing for the permanent stationing of United States Armed Forces in Iraq" or "to exercise United States control of the oil resources of Iraq."

The Bush administration is negotiating a long-term agreement with Iraqi Prime Minister Nouri al-Maliki. The agreement is to include the basing of US troops in Iraq after 2008, as well as security guarantees and other economic and political ties between the United States and Iraq.

The negotiations have drawn fire in part because the administration has said it does not intend to designate the compact as a "treaty," and so will not submit it to Congress for approval. Critics are also concerned Bush might lock the United States into a deal that would make it difficult for the next president to withdraw US troops from Iraq.

"Every time a senior administration official is asked about permanent US military bases in Iraq, they contend that it is not their intention to construct such facilities," said Senator Robert P. Casey Jr., Democrat of Pennsylvania, in a Senate speech yesterday. "Yet this signing statement issued by the president yesterday is the clearest signal yet that the administration wants to hold this option in reserve."

Several other congressional Democrats also took issue with the signing statement.

"I reject the notion in his signing statement that he can pick and choose which provisions of this law to execute," said Speaker Nancy Pelosi, Democrat of California. "His job, under the Constitution, is to faithfully execute the law - every part of it - and I expect him to do just that."

Bush's signing statement did not explain the specific basis for his objection to the prohibition on establishing permanent military bases in Iraq.