US President George W. Bush announced on Thursday a partial troops pullback from Iraq by next summer, while warning a full withdrawal could endanger the Iraqi government's survival.

"We must help Iraq defeat those who threaten its future and also threaten ours," Bush said in a prime-time televised address to the nation.

The president said 2,200 Marines are coming home immediately and will not be replaced, and an Army brigade of 3,500 will be out of Iraq by Christmas.

These units were already scheduled to come home, but they will not be replaced.

Calling the speech a "return on success," the president said he will withdraw five brigades by mid-July, approximately 23,000 troops, leaving about 137,000 US troops in place by next summer.

"The principle guiding my decisions on troop levels in Iraq is return on success," Bush said.

"The more successful we are, the more American troops can return home. ... Our success in meeting these objectives now allows us to begin bringing some of our troops home."

While Bush attempts to portray the redeployment as a troop withdrawal, there will actually be 7,000 more troops in Iraq next summer than there were before Bush deployed additional forces to Iraq in January as part of a troop surge plan to quell sectarian violence.

In his over 16-minute address, Bush also noted that any troop pullback will be heavily conditioned on stability in Iraq -- far from the rapid withdrawal of troops wanted by Democratic leaders in Congress.

Bush also attempted to convince the public he is applying pressure on Iraqi national leaders to work together to achieve political reconciliation.

"The government has not met its own legislative benchmarks, and in my meetings with Iraqi leaders, I have made it clear that they must," Bush said.

(Xinhua News Agency September 14, 2007)