Blair held talks with Interim Prime Minister Ayad Allawi and Iraqi election officials, who called heroes for carrying out their work despite attacks by insurgents. Three members of Iraq's election commission were dragged from the car and killed this week in Baghdad.
"I said to them that I thought they were the heroes of the new Iraq that's being created, because here are people who are risking their lives every day to make sure that the people of Iraq get a chance to decide their own destiny," Blair said during a joint news conference with Allawi.
Blair, whose trip to Iraq hadn't been disclosed for security reasons, urged Iraqis to back the Jan. 30 national vote, the first since Saddam Hussein's ouster.
"Whatever people's feelings and beliefs about the removal of Saddam Hussein, and the wisdom of that, there surely is only one side to be on in what is now very clearly a battle between democracy and terror," said.
The British leader said that apart from the insurgents' violence, "there is another choice for Iraq: the choice is democracy, the choice is freedom, and our job is to help them get there because that's what they want."
In other developments:
Allawi said his government was committed to holding the elections as scheduled next month, despite calls for their postponement owing to the violence.
"We have always expected that the violence would increase as we approach the elections," Allawi said. "We now are on the verge, for the first time in history, of having democracy in action in this country."
Blair said that as the U.S.-led multinational force, in which British troops are serving, trains and improves the Iraqi security forces, "that brings forward the day that the multinational force can leave" Iraq. The presence of foreign troops in Iraq is strongly opposed across the Arab world.
Blair flew into the Iraqi capital about 11 a.m. aboard a British military transport aircraft from Jordan. A Royal Air Force Puma helicopter flew from Baghdad airport to the city center, escorted by U.S. Black Hawk helicopters.
It was Blair's first visit to Baghdad and his third to Iraq since the dictator Saddam Hussein was toppled in April 2003. Blair visited British troops stationed around the southern Iraqi city of Basra in mid-2003 and in January. President Bush had paid a late night visit to U.S. troops in Baghdad in November 2003.
The British leader was a key supporter of the U.S.-led invasion of Iraq that toppled Saddam. His decision to back the U.S. offensive angered many lawmakers in his governing Labour Party and a large portion of the British public.
Britain has some 9,800 troops in Iraq, stationed mostly around Basra. It is the second largest contributor to the multinational force after the United States.
Before meeting Allawi, Blair met the commander of the multinational force, U.S. Army Gen. George W. Casey, and the senior British military officer in Iraq, Lt. Gen. John Kiszely.
In ongoing violence on Tuesday, a U.S. jet bombed a suspected insurgent target in central Iraq and gunmen assassinated an Iraqi nuclear scientist north of Baghdad.
Elsewhere, five American soldiers and an Iraqi civilian were wounded when the Humvee they were traveling in was hit by a car bomb near Hawija, 150 miles north of Baghdad, the U.S. military said.
The bloodshed came a day after Allawi blamed the upsurge of violence on a campaign by insurgents to foment sectarian civil war as well as derail legislative elections set for Jan. 30.
Allawi said the mainly Sunni Muslim insurgents, blamed for Sunday's bombings in the Shiite holy cities of Najaf and Karbala, want to "create ethnic and religious tensions, problems and conflicts ... to destroy the unity of this country."
The coordinated bombings killed 67 people and injured almost 200 in one of the bloodiest attacks on civilians this year.
Early Tuesday, a U.S. aircraft engaged an "enemy position" with precision-guided missiles west of Baghdad, the military said.
Hamdi Al-Alosi, a doctor in a hospital in the city of Hit, said four people were killed and seven injured in the strike. He said the attack caused damage to several cars and two buildings.
The U.S. military spokesman could not confirm the casualties.
In Baqouba, a city 35 miles northeast of Baghdad, unidentified assailants shot dead an Iraqi nuclear scientist as he was on his way to work, witnesses said.
Taleb Ibrahim al-Daher, a professor at Diyala University, was killed as he drove over a bridge on the Khrisan river. His car swerved and plummeted into the water.
And in northern Iraq, insurgents set ablaze a major pipeline used to ship oil to the Turkish port of Ceyhan, a principal export route for Iraqi oil, an official with the North Oil CO. said Tuesday.
Firefighters were on the scene, 70 miles southwest of Kirkuk, trying to extinguish the fire.
Insurgents have often targeted Iraq's oil infrastructure, repeatedly cutting exports and denying the country much-needed reconstruction money.