WASHINGTON – President Bush on Sunday embarked on nearly 24 hours of somber observances at the three sites where terrorists wrought death and destruction and transformed his presidency.

He intended to offer few words during appearances at ground zero in New York where the World Trade Centers fell, in the Pennsylvania field where one of the hijacked planes hurtled to the ground and at the Pentagon crash site. But Americans will hear more from him during a prime-time address Monday night from the Oval Office.

Even before Bush left the capital, surrogates from Vice President Dick Cheney spent the Sept. 11 anniversary’s eve vigorously defending the administration’s record on improving the national defense over the past five years.

“There has not been another attack on the United States,” Cheney said on NBC’s “Meet the Press.” “And that’s not an accident.”

On television and newspaper opinion columns, Cabinet secretaries and agency heads sought to make the case that the government under Bush has made important changes that have lessened the risk of attack.

Cheney focused on anti-terrorism efforts that he has been instrumental in supporting: a warrantless wiretapping program to monitor the international communications of people in America with suspected ties to al-Qaida; a system to track international financial transactions; and tough policies on the detention and interrogations of suspected terrorists.

Democrats, however, contend the administration has fallen short because so little cargo is inspected at U.S. ports and chemical plants, and other high-value sites are vulnerable.

“I think we’re in trouble,” said Democratic National Committee chairman Howard Dean. “We have not pursued the war on terror with the vigor that we should have because we’ve gotten bogged down in this civil war in Iraq.”

The fifth-year anniversary falls less than two months before elections.