President Bush says Iran must stop arming militants who are attacking U.S. troops in Iraq.  VOA White House Correspondent Scott Stearns reports, Mr. Bush's speech to a veterans group is part of a White House effort to restore public support for the war in Iraq.

President Bush told a meeting of the American Legion, America's largest veterans' group, that winning the war in Iraq is vital to America's long-term security and the future of the Middle East.

He says extremists in the region are inspired by two strains of violent Islamic radicalism that are closing in on Iraq in an effort to bring down its young democracy.

The president says Sunni extremism, embodied by al-Qaida and its allies, is responsible for the September 11 terrorist attacks in New York and Washington as well as violence against fellow Muslims in Algeria, Jordan, Egypt, and Saudi Arabia.

Mr. Bush says Shia extremism is embodied by Iran, which he says threatens the security of nations everywhere by actively pursuing technology that could be used to develop nuclear weapons.

He told the military veterans that Iran is funding Hezbollah militants and is arming Iraqi extremists to attack U.S. troops.

"Some say Iran's leaders are not aware of what members of their own regime are doing," Mr. Bush said. "Others say Iran's leaders are actively seeking to provoke the West.  Either way, they cannot escape responsibility for aiding attacks against coalition forces and the murder of innocent Iraqis.  The Iranian regime must halt these actions, and until it does, I will take actions necessary to protect our troops."

Mr. Bush says he has authorized U.S. military commanders in Iraq to confront what he calls "Tehran's murderous activities."

A majority of Americans now believe the war in Iraq is a mistake.  A public-opinion poll by CBS News this month says more than two-thirds of Americans disapprove of the president's handling of the war in Iraq.

White House officials say the speech, along with last week's appearance before the Veterans of Foreign Wars, is meant to set the broader context for the Iraq conflict before next month's presidential report to Congress on the impact of the January decision to send more troops to Iraq.

While the president says he will make no decisions on troop levels until after the September 15th report to Congress, he made clear to the American Legion that withdrawing before the war is won would be a mistake.

"We have seen what these enemies will do when American forces are actively engaged in Iraq," Mr. Bush said. "And we can envision what they would do if they were emboldened by American forces in retreat."

The president says the challenge in Iraq is that either the forces of extremism advance their interests or the forces of freedom succeed and advance America's interests.  He says the most important way to counter the ambitions of al-Qaida and Iran is to win the fight in Iraq.