President Bush, facing a critical juncture in the war, urged Democrats and Republicans on Saturday to unite and back the war strategy he'll lay out shortly for the next chapter of U.S. involvement in Iraq.

After days of diplomacy at an Asia-Pacific summit here, Bush is gearing up for contentious debate back home next week on Capitol Hill.

Democratic leaders want to pass legislation that would bring troops home beginning this fall, but they don't have enough votes to stop Bush from sticking to his war strategy. Republican leaders think they can maintain the support of most GOP lawmakers, especially with recent security improvements in Anbar province and Baghdad.

In his weekly radio address, Bush recounted his surprise trip to the desert in western Iraq, where he met with Iraqi leaders and local sheiks who have joined U.S.-led coalition forces in fighting Al Qaeda.

"Together we have driven Al Qaeda out of strongholds in Anbar," Bush said. "The level of violence is down. Local governments are meeting again. Young Sunnis are joining the police and army. And normal life is returning.

"The people of Anbar have seen that standing up to the terrorists and extremists leads to a better life," Bush said. "And Anbar has shown that improving security is the first step toward achieving economic progress and political reconciliation."

Senate Majority Leader Harry Reid's assessment of the situation on the warfront had a different tone. In the Democratic radio address, the Nevada senator repeated his contention that Bush had misled the country into "an ill-planned war in Iraq" before finishing the job of destroying Al Qaeda.

The U.S. military is not to blame for setbacks in the war, Reid added. "These are President Bush's failures — and it is long past time for him to change his flawed policies," he said.

Noting that Gen. David Petraeus, the top commander in Iraq, was scheduled to deliver a report to Congress, Reid said the report would "pass through the White House spin machine, where facts are often ignored or twisted, and intelligence is cherry-picked." Nonpartisan assessments show little political progress by Iraqi officials and that the violence had not subsided, he said.

Next week is a vital one for Bush and the course of the war, which will define his legacy.

Petraeus and Ryan Crocker, the U.S. ambassador to Iraq, testify to Congress about whether sending 30,000 more U.S. troops to Iraq has helped stabilize the nation.

Also, the nation marks the sixth anniversary of the Sept. 11 attacks on Tuesday, and Bush hands lawmakers his latest progress report on the war. That report comes at a critical juncture, with Congress just back from its summer vacation, and the administration seeking fresh funding for an unpopular war.

Bush said he will speak to the nation next week about the recommendations from Petraeus and Crocker about how to proceed in Iraq. The exact timing of that address has not been announced.

"I will discuss the changes our strategy has brought to Iraq. I will lay out a vision for future involvement in Iraq — one that I believe the American people and their elected leaders of both parties can support," Bush said.

"By coming together on the way forward, we will strengthen Iraq's democracy, deal a blow to our enemies, secure interests in the Middle East, and make our Nation safer," he said.

Lawmakers are already gearing up for next year's elections. GOP members are being targeted by anti-war candidates, buoyed by public polls that show Americans are weary of the war.

At the summit in Australia, the president pushed fellow leaders to revive stalled global trade talks and cooperate on climate change. The Pacific Rim leaders agreed Saturday to adopt a joint position on global warming statement that includes goals on reducing energy intensity.

Yet for Bush, the issue of Iraq punctuated his sit-downs with Japanese Prime Minister Shinzo Abe and Indonesia's President Susilo Bambang Yudhoyono, leader of the world's most populous Muslim nation.

After the meeting with Abe, Bush countered Usama bin Laden's latest video message, in which he mocks the democratic system of government in the United States and lambastes the Bush administration for initiating the war in Iraq.

Without mentioning the wanted terrorist by name, Bush noted how bin Laden spoke of Iraq.

"If Al Qaeda bothers to mention Iraq it's because they want to achieve their objectives in Iraq, which is to drive us out and to develop a safe haven. And the reason they want a safe haven is to launch attacks against America, or any other ally," Bush said. "And therefore, it's important that we show resolve and determination, to protect ourselves, to deny Al Qaeda safe haven, and to support young democracies, which will be a major defeat to their ambitions."