He did not set a timetable for these goals.
Bush vowed to interrupt what he called the "flow of support" from Iran and Syria for attacks on US forces in Iraq, as he unveiled his revamped Iraq war strategy.
He also said that Saudi Arabia, Egypt, Jordan and the Gulf states "need to understand that an American defeat in Iraq would create a new sanctuary for extremists - and a strategic threat to their survival".
Senior administration officials said 17,500 troops would go to Baghdad and 4,000 to violence-wracked Anbar province, with the first wave of troops expected to arrive in five days.
Others will come in additional waves, joining about 130,000 already in Iraq. Under the plan, the Iraqi government will deploy additional Iraqi troops to Baghdad with a first brigade deploying on February 1 and two more by February 15.
They are to sweep Baghdad neighbourhoods regardless of sectarian pressures and follow a chain of command leading to Nuri al-Maliki, the Iraqi prime minister.
Bush acknowledged mistakes that had been made in Iraq and that more US and Iraqi troops should have been used in military operations.
|"The plan will cover all those neighbourhoods that have been a source of violence, regardless of whether the sources are sectarian militias, terrorists, foreign fighters or criminals"|
Hoshyar Zebari, Iraqi Foreign Minister
More than 3,000 US troops have died in Iraq since the US-led invasion in March 2003 to topple Saddam Hussein and dismantle his supposed weapons of mass destruction.
By summer, perhaps August, US officials will be able to determine whether the new strategy is working, one official said. The cost of the new troop increase would be around $5.6bn.
An additional $1.2bn would finance Iraqi rebuilding and jobs programmes with the aim of cutting down on the supply of new recruits for militias.
Bush is calling for turning over security of all Iraqi provinces by November, but officials caution that this did not represent a timetable for a US pullout. Iraqis currently control only three of 18 provinces.
A USA Today/Gallup poll said Americans oppose the idea of increasing troop levels in Iraq by 61 per cent to 36 per cent.
On Wednesday, Hoshyar Zebari, the Iraqi foreign minister, interviewed on Al Jazeera in Baghdad, said: "The plan is that Iraqi forces will take the lead in the cleaning-up of streets and neighbourhoods of Baghdad ... that's how this plan differs from previous plans. This plan will not discriminate.
"The plan will cover all those neighbourhoods that have been a source of violence, regardless of whether the sources are sectarian militias, terrorists, foreign fighters or criminals."
On the other hand, Riyad Kahwaji, a Dubai-based defence analyst, told Al Jazeera that Bush is trying to reverse his policy on Iraq.
"Now, after nearly four years and all those casualties, support for the presence of US troops in Iraq has dwindled," he said on Wednesday.
However, 20,000 US troops were unlikely to make a difference to the country's overall security situation, Kahwaji said.
"The level of insurgency is higher than before and so is the possibility of civil war, and if Bush's obvious objective is to control Baghdad, then 20,000 extra troops might be enough to clean up Baghdad of militia men.
"But they will need better luck with the rest of Iraq."