WASHINGTON, Dec 28: Iraq's deadly insurgency will rage on, no matter what the outcome of next month's elections may be, US Secretary of State Colin Powell said on Tuesday, amid new questions about the polls after a boycott call by the main Sunni Muslim party.

In a round of television interviews, Powell expressed concern about the decision by the Iraqi Islamic Party to spurn the January 30 elections but said coalition and Iraqi forces were doing their utmost to make Sunni areas safe for Iraqis to vote.

"It won't be perfect, but I think people want to vote, and they're prepared to take some risk to go out and vote," he told Fox News. "In most of the country, the election will go off well; it's relatively secure."

The elections for a 275-seat national assembly that will form a new government and draft a permanent constitution have been clouded by escalating violence and intimidation by guerillas. He said this would not stop with the ballot.

"These insurgents are determined to have no representative government. They want to go back to a tyranny," Powell told CBS News. "And so the insurgency will continue and the insurgency will have to be defeated by coalition forces."

The United States has increased its troop strength in Iraq from 138,000 to 150,000 for the election. But Powell said the ultimate job of taming the fighters would fall to Iraqi forces "that we are building up as rapidly as we can."

Washington has insisted Iraq's first elections since the ouster of Saddam Hussein last year will be a milestone in its transition to democracy. But many analysts question whether the result will be credible, given the level of bloodshed and threats.

Asked about the Iraqi Islamic Party's move to shun the vote, Powell said "it's a concern" but expressed hope that its members would change their mind. "We're doing everything we can to improve the security in the Sunni areas," he said.

Adding to the pressure on Iraqis was a voice recording attributed to Osama bin Laden and aired on Al-Jazeera television on Monday, which branded those who participate in the vote "infidels."

The voice also anointed Abu Musab al-Zarqawi, blamed for some of the worst bombings, assassinations and beheadings in Iraq, as Osama's 'emir' in the war-torn country.

The US Central Intelligence Agency indicated it is relatively certain that the voice on the tape is that of Osama, according to an intelligence official. "We assessed with moderate confidence that it is the voice of Osama bin Laden," the official said on Tuesday on condition of anonymity.