Perpetrators of violence in Iraq are trying to provoke a civil war to prevent democracy from blooming in the Arab nation, but Iraqis aren't being led into it, President Bush said Monday.

The restraint called for by sectarian leaders in the face of massive provocation, particularly after the bombing of a Shiite shrine in Sumarra last month, shows that the Iraqis are committed to freedom, he said.

"Immediately after the attack, I said that Iraq faced a moment of choosing. And in the days that followed, the Iraqi people made their choice. They looked into the abyss and did not like what they saw," Bush told the Foundation for the Defense of Democracies, a non-partisan, non-profit policy institute at George Washington University in Washington, D.C.

"We saw the leadership of Sunni and Shia clerics who joined together to denounce the bombing and call for restraint. ... Iraq's leaders know they must put aside their differences, reach out across political, religious and sectarian lines and form a unity government that will earn the trust and the confidence of all Iraqis," Bush said. "The only path for a future of peace is a path of unity."

Bush said part of the reason a violent mob response was deterred is that Iraqi security forces are working more effectively to quell anger. Iraqi forces were able to disperse enraged crowds that formed after the Sumarra bombing. Before and since then, they have "manned checkpoints, increased patrols and ensured that peaceful demonstrators were protected while those who turned to violence were arrested."

He added that the number of Iraqi battalions has increased to more than 130, with 60 of them leading operations and assuming responsibility for more territory.

"Iraqi forces are now conducting more independent operations throughout the country than do coalition forces," he said.

Bush said the United States is hoping to build on three angles — security, democracy and economy. While focusing on the security effort for the majority of his speech, the president said a new Parliament, which is meeting next week, will soon form a new government. He asked Americans to "not lose our nerve" as the fruits of change are achieved.

The president's remarks are the first in a series scheduled ahead of the March 20 anniversary of the 2003 U.S.-led invasion. The White House says as commander in chief, it's important for Bush to update the American people in a time of war, even three years after it began.

Aides say the president wants to put into context the latest violence in Iraq. On Monday, 55 people died in mortar and car-bomb attacks in marketplaces, bringing the total over two days to more than 200.

The latest AP-Ipsos poll found that seven in 10 Republicans and nine in 10 Democrats saying a civil war is likely in Iraq. Both Iraqi President Jalal Talabani and radical Sunni cleric Muqtada al-Sadr on Monday tried to put the blame for the recent attacks on Al Qaeda in Iraq, and not the religious sects within the country.

But Senate Minority Leader Harry Reid said Bush's attempts to paint a rosy picture disguise the ongoing problems in Iraq.

"Three years ago this week, the Bush administration engaged in a final sales pitch to convince Americans that war in Iraq was imperative. Members of the Bush administration simultaneously played up the risks (Saddam) Hussein's regime posed to the United States while discounting the difficulty of executing a successful military operation," Reid said. "As President Bush kicks off a barnstorming effort to shore up support for his administration's policies, it is worth pausing to review some of the statements that led us to our current situation. It's time for competent leadership."

Reid then pointed to news articles that say sectarian violence has eclipsed terrorism, U.S. forces are preparing for civil war and Iraqi troops' strength has been downgraded.

As if on cue, Bush responded: "I wish I could tell you the violence is waning and the road ahead will be smooth. It will not. There will be more tough fighting and more days of struggle, and we will see more images of chaos and carnage in the days and months to come."

Nonetheless, he said, "terrorists are losing on the field of battle so they are fighting this war though the pictures we see on the television and in the newspapers every day. They're hoping to shake our resolve and force our retreat. They are not going to succeed."

During his speech, the president acknowledged that some militias had infiltrated the Iraqi security forces, and were being weeded out. He also conceded that Iraqi troops are not being trained as quickly as the Department of Defense had hoped.

While Iraqi troops stand up, American forces will step down, Bush said in a oft-voiced refrain. Meanwhile, he said, the United States is taking new efforts to stop the use of improvised explosive devices, the roadside remote control bombs that have wounded and killed many U.S. soldiers. That is also the subject of a closed Senate Armed Services Committee briefing on Monday afternoon.

Bush said the approach involves "targeting, training and technology." He said bomb makers are being stopped before they can build or plant the bombs, and weapons caches are being uncovered with the help of Iraqi people.

"The number of tips from Iraqis has grown from 400 last March to 4,000 in December," he said. The president said the Pentagon recently gathered together 600 leaders in sciences and military technology to find ways to blunt the power of IEDs.

"Nearly half the IEDs in Iraq are being found and disabled before they are detonated," he said, adding that casualty numbers from IEDs have been cut in half as a result.

Bush, however, would not describe any of the technology being built, saying that terrorists are quick to adapt to new technologies, which already had been described in one Internet article and countered by terrorists.

The president added that many IEDs and components seized by coalition forces were clearly produced in Iran.

"Such actions, along with Iran's support for terrorism and its pursuit of nuclear weapons, are increasingly isolating Iran," he added.

FOX News' Molly Henneberg and The Associated Press contributed to this report.