Washington: Admitting for the first time that his administration's previous strategy in Iraq had failed, US President George W Bush has announced that he is sending more than 20,000 more troops to buttress 130,000 already there to quell sectarian violence in the strife-torn country.

However, he did not set any time table for the troops stay in the country and rejected the Democrats' suggestion for start withdrawing the forces, saying it would deepen the crisis.

In a 20-minute address to the nation, Bush accepted that he had made mistake by not deploying enough troops or resources which led to the country's descent into violence and increasing sectarian killings.

"The situation in Iraq is unacceptable to American people and it is unacceptable to me. Where mistakes have been made, the responsibility lies with me," he said, a remark analysts noted, was far cry from his earlier assertions that the United States was making progress towards establishing a democracy in Iraq.

The address laying out new strategy was also marked by blunt warning to Iraqi government that American commitment is not open-ended and that it would lose support of both American and Iraqi people if it did not fulfill its promises.

He also signaled that he would not compromise with Iran or Syria or involve them in the wider strategy to bring peace in the region.

Accusing them of allowing insurgents to use their territory, he said "We will interrupt the flow of support from Syria and Iran. And we will seek out and destroy the networks providing advanced weaponry and training to our enemies".