"We're determined to deny radical groups the support and sanctuary of outlaw regimes. State sponsors like Syria and Iran have a long history of collaboration with terrorists and they deserve no patience from the victims of terror," Bush said.

During the president's speech on terrorism, a heckler yelled: "Mr. President, what is terrorism? What is terrorism? Step down now." The man was escorted out and others in the audience booed the heckler.

The United States has repeatedly expressed concern over Iran and its nuclear energy program, which it suspects could be a cover for nuclear weapons development. Iran insists the program is intended for civilian electricity generation.

And Western countries condemned recent comments by Iran's President Mahmoud Ahmadinejad calling for Israel to be wiped off the map.

Last year, the United States and its allies, in fighting proliferation of deadly weapons, "have stopped more than a dozen shipments of suspected weapons technology including equipment for Iran's ballistic missile program," Bush said.

"This progress has reduced the danger to free nations, but it has not removed it," he said. "Evil men who want to use horrendous weapons against us are working in deadly earnest to gain them. And we are working urgently to keep weapons of mass murder out of the hands of the fanatics," Bush said.

The Bush administration justified the March 2003 invasion of Iraq by saying Baghdad posed a threat because it had stockpiles of chemical and biological weapons and was pursuing nuclear weapons. No weapons of mass destruction were found in postwar Iraq.

The United States accuses Syria of allowing foreign fighters to cross its border into Iraq to fuel the insurgency, and last week U.N. investigators blamed Syrian and Lebanese security officials of organizing the murder of former Lebanese Prime Minister Rafik Hariri on February 14.

The United States and France have threatened Syria with economic sanctions if it does not cooperate fully with the U.N. probe into Hariri's assassination.

"The United States makes no distinction between those who commit acts of terror and those who support and harbor them because they are equally guilty of murder," Bush said.

"We're determined to deny the militants control of any nation which they will use as a home base and a launching pad for terror," he said.