WASHINGTON — World leaders who put on a show of unity to commemorate the legendary D-Day offensive that changed the course of the Second World War are back to dealing with deep divisions over Iraq this week.

President George W. Bush, who's hosting the Group of Eight Summit on Georgia's Sea Island, starting Tuesday, needs all the support he can get among European leaders who vociferously opposed the U.S. invasion and want to speed the Middle East country's transition to full sovereignty.

Bush got a boost over the weekend when Iraq's new interim prime minister, Ayad Allawi, formally invited U.S. troops to stay in Iraq beyond the June 30 transfer of power from American hands, hailing it as a "positive step forward."

American and French officials said the development could lead to a new United Nations resolution that would provide international approval and perhaps attract more money and troops for Iraq.

But it was clear there's still considerable tension between Bush and hardline critic Jacques Chirac when the two met Saturday in Paris.

Bush didn't endear himself to the French leader with recent comparisons of the Iraq war and the fight against Nazi Germany in the Second World War.

"History does not repeat itself," Chirac said, "and it is very difficult to compare historical situations that differ. The situation in Iraq has to be contained, has to be mastered. We have to roll up our sleeves ... Perhaps we will succeed."

An appearance of goodwill among leaders and more support for his Iraq plan is crucial to Bush's fight for re-election this fall.

Buffeted by continuing Iraqi bloodshed and the prisoner abuse scandal, the president is facing his lowest-ever approval ratings at home as he tries to combat enmity abroad.

While Iraq will doubtless top the agenda, leaders gathering on the exclusive vacation island off the Georgia coast -- protected by the most extensive security measures ever taken for such an event -- will also discuss anti-terrorism, U.S. proposals for broader democracy in the Middle East, weapons reduction, global warming and world economic issues.

But some analysts weren't expecting a lot of progress on the most contentious items among leaders burdened by economic or political troubles at home. Even U.S. officials were downplaying the chances for substantial progress on Iraq.

Prime Minister Paul Martin, in the middle of a dicey election campaign, is ducking out a day early to get back on the road.

He's expected to discuss Canada's $300-million Cdn commitment to help in Iraq and efforts in Afghanistan when he meets Tuesday with Bush.

The two will also likely broach the long-running softwood lumber dispute and the president's promise in April to drop the ban on Canadian cattle that has yet to yield results.

Other topics include rising gas prices and U.S. and European agricultural subsidies.

In the broader summit, Martin hoped to make headway on global poverty, including how the wealthy Group of Eight countries can facilitate private-sector development in developing countries.

Other G-8 countries were expected to push for progress on less divisive issues, including HIV-AIDS initiatives, slave labour and dismantling stocks of nuclear and chemical weapons.

Besides the United States, Canada and France, the other G-8 countries include Britain, Germany, Italy, Russia and Japan.

Only Britain, Italy and Japan have forces in Iraq.