"In the immediate phase ahead of us between now and the end of June we will actually see an increase in attacks, because the people who are against us now realize that there's huge momentum behind both the economic and political reconstruction of this country," L. Paul Bremer said in an interview with Associated Press Television News.
Bremer's comments come as daily reports of violence continue in Iraq. In the latest incident, a bomb exploded near a Baghdad mosque as a U.S. military convoy passed by Friday, killing an American soldier and two Iraqis.
According to a Nov. 15 agreement between the U.S.-led coalition and Iraq's Governing Council, caucuses will be held across Iraq to elect delegates who will convene by the end of May. One month later, the delegates will elect a transitional government with full sovereign powers, formally ending the U.S.-led occupation.
"The dead-enders can see that all this, plus the fact that the Iraqi people will get their sovereignty back, spells trouble for them," Bremer said.
"So I think we will see a phase now when we will actually see increased attacks," he said.
A total of 79 U.S. soldiers died in Iraq in November. Another 25 allied troops were also killed, making it the deadliest month for the coalition since the invasion of Iraq on March 20.
In other developments:
The dead soldier in Friday's attack was traveling in a three-vehicle convoy when a roadside bomb exploded nearby, the military said in a statement. A spokesman had initially denied reports of U.S. casualties.
Most of the civilian casualties were passengers on a bus that was badly damaged in the blast near the al-Samarrai mosque in the New Baghdad section of the capital.
Karim Abdullah Muslim, the head of emergency services at the nearby al-Kindi hospital, said a man and a woman died and 13 people were injured.
Haitham Rashid, a passenger on the bus, said about two dozen people were aboard the vehicle at the time of the blast.
Haidar Aziz Kazim, an 11-year-old schoolboy, said he had been shopping with his mother and aunt at the time.
"I blame Saddam Hussein for what happened," said Kazim, who was in the hospital with wounds to his legs. "They are hurting ordinary Iraqis, not the Americans."
Meanwhile, U.S. troops cordoned off part of the main highway after a fire destroyed an armored personnel carrier in Mishada, 20 miles north of the capital.
Capt. Brian Ridley said the fire was caused by a faulty heater, which caused ammunition inside the vehicle to explode. No casualties were reported, he said.
Separately, about 500 people rallied Friday in central Baghdad to call for an end to terrorist attacks against civilians. Participants carried banners reading "No to terrorism" and expressed support for the U.S.-led coalition that has governed Iraq since ousting Saddam Hussein in early April.
In a Friday sermon in the town of Kufa south of Baghdad, radical Shiite cleric Muqtada al-Sadr threatened to call a general strike in the holy city of Najaf if U.S. occupation forces do not set free members of his militia group by the start of the next Arabic month, which falls in about 20 days.
Al-Sadr did not say how many militiamen of the group — known as Imam al-Mahdi's Army — were in detention.