U.S. President George W. Bush acknowledged Wednesday that his strategy in Iraq has not been working as he announced a new plan to deploy more than 20,000 more soldiers and spend billions more dollars.

"It's clear that we need to change our strategy in Iraq," Bush said in a televised address to the nation, admitting mistakes had been made since the U.S. led the invasion of Iraq in 2003.

U.S. President George W. Bush said in the televised address: 'Where mistakes have been made, the responsibility rests with me.'
(CBC)

In outlining his new plan, which includes sending 21,500 more American troops into Iraq, Bush said the current situation in Iraq was "unacceptable."

"Where mistakes have been made, the responsibility rests with me," he said.

Bush said there were two main reasons why past efforts have failed to quell the violence in Baghdad: there were too many restrictions on the troops, and there weren't enough troops to secure neighbourhoods that were cleared of insurgents, who would return.

About 132,000 U.S. troops are already posted in Iraq. Under the plan unveiled Tuesday, 17,500 more soldiers would be deployed to the unstable capital and the other 4,000 would go to the violent Anbar province.

"This time, we will have the force levels we need to hold the areas that have been cleared," Bush said.

Bush also said Iraqi and American forces would have "a green light" to enter neighborhoods where political and sectarian interference had prevented them from entering.

The president had been crafting his new Iraq strategy for nearly three months, consulting in December with top U.S. generals and defence department officials.

"Our military commanders reviewed the new Iraqi plan to ensure that it addressed these mistakes. They report that it does. They also report that this plan can work," he said.

He released his new plan amid increasing anti-war sentiment in the United States. An Ipsos poll conducted in December showed only 27 per cent of Americans approved of Bush's handling of the war, which has cost the United States more than $400 billion US and has claimed the lives of more than 3,000 soldiers.

But Bush refused to retreat on Tuesday, warning that it would "force a collapse of the Iraqi government" and be a "disaster for the United States."

"Such a scenario would result in our troops being forced to stay in Iraq even longer and confront an enemy that is even more lethal," he warned.

"If we increase our support at this crucial moment and help the Iraqis break the current cycle of violence, we can hasten the day our troops begin coming home."

Bush's plan also commits to:

• Spend $6.8 billion US more to fund the extra troops and do reconstruction work.
• Create nine new provincial reconstruction teams in Baghdad and Anbar, adding to the 10 teams that already exist. The teams, under U.S. State Department control, will provide small loans to businesses and administer other economic aid.

Iraq's government warned to disband militias

But the president also called upon Iraqis to meet their responsibilities, which include disbanding Shia militias and readying their forces to handle security operations in Baghdad.

"America's commitment is not open-ended," Bush said. "If the Iraqi government does not follow through on its promises, it will lose the support of the American people and it will lose the support of the Iraqi people."

That echoes earlier comments by the president, who said that before more troops are sent, Iraq's government must deal with the political and economic problems that have gripped the country and take specific steps to curb growing sectarian violence between Sunni and Shia Muslims.

Bush said America would hold the Iraqi government to the benchmarks it has announced, which includes Iraqi government plans to take responsibility for security in all of Iraq's provinces by November.

Democrats ready to battle Bush's plans

Democrats immediately pounced on Bush's new plan, saying Iraq is not doing enough to solve its problems.

"Iraqi political leaders will not take the necessary steps to achieve a political resolution to the sectarian problems in their country until they understand that the U.S. commitment is not open-ended," said a joint statement from Senate Majority Leader Harry Reid, Democratic Whip Senator Richard Durbin, House Speaker Nancy Pelosi and House Majority Leader Steny Hoyer.

"Escalating our military involvement in Iraq sends precisely the wrong message and we oppose it."

Some Republicans also expressed opposition to the new strategy.

"If Iraq is going to fulfill its role as a sovereign and democratic state, it must start acting like one. It is for this reason that I oppose the proposal for a troop surge," said Senator Norm Coleman, a Republican from Minnesota.

"I do not believe that sending more troops to Iraq is the answer. Iraq requires a political rather than a military solution," said Senator Sam Brownback, a Republican from Kansas.

But Senator Joe Lieberman, a former Democrat who supported the Iraq invasion and now sits as an Independent, praised the plan.

"I applaud the president for rejecting the fatalism of failure and pursuing a new course to achieve success in Iraq."

Democrats, who recently took control of the U.S. Senate and the House of Representatives, plan to make their opposition to the troop buildup official.

Pelosi pledged to hold a vote on the increase.

In the Senate, Democrat Edward Kennedy has sponsored legislation requiring Bush to get congressional approval before sending more troops to Iraq.

With files from the Associated Press