By Barnaby Mason BBC's Diplomatic Correspondent

Tensions both inside and outside of the summit are expected

President George Bush is about to step onto French soil for the first time since France led the bitter international opposition to the American-British invasion of Iraq.

He is attending this year's G8 summit, bringing together the world's biggest industrialised democracies plus Russia.

There is talk of looking to the future and working together, but that does not disguise transatlantic disagreements on a whole range of issues.

The Bush administration wants people to move on from the quarrels over Iraq to an agenda for the 21st century.

Besides poverty and development, that includes the war on terrorism, stopping weapons proliferation and resolving the Israeli-Palestinian conflict.

France and other opponents of the Iraq war in the G8 are also making positive noises about co-operation.

But in an interview with the Financial Times a few days before the summit, President Jacques Chirac made clear he still regarded the war as illegitimate.

In fact, French officials think the disorder in Iraq and the recent suicide bombings in Saudi Arabia suggest they were right to warn of the consequences.

Mr Chirac repeated his view that Washington had a unilateralist vision of the world; while he saw it as multi-polar - the two essential poles being Europe and the United States.

In the run-up to this summit at Evian-les-Bains, on the southern shore of Lake Geneva, transatlantic rivalry was certainly on display.

President Bush announced a contribution of up to $15bn in the battle against Aids, structuring the measure as a challenge so that the final amount depends on the Europeans and others taking similarly generous action.

He also accused them of damaging efforts to feed the hungry in Africa by opposing exports of genetically modified food.

GM food is already one of the sharpest transatlantic disputes - the United States is taking action in the World Trade Organisation against the EU's four-and-a-half year de facto moratorium on approving new GM varieties.

Africa focus

Mr Bush's pre-emptive strikes were partly designed to counter Mr Chirac's proposal in February for the US and the EU to stop subsidised agricultural exports to Africa, where they undermine local producers. He even made a similar call of his own.

The trouble is - according to many observers and development campaigners - neither leader means what he says on open access for poor countries' farm exports.

Africa is intended to top the G8 agenda

The US criticises the European subsidy system of the Common Agricultural Policy; the EU criticises Washington's export credits and other subsidies to American farmers. Senior UN officials accuse them both of grandstanding.

It is hard to see a substantial initiative on this front emerging from the Evian summit.

Mr Chirac and others would like to make further progress on giving the poorest countries access to cheap drugs.

Countries like Brazil and India, which can manufacture their own versions, were helped by an agreement in 2001, but sub-Saharan Africa, for example, was left out.

Africa is intended to be a centre-piece of the summit.

Five African leaders will present a report on progress in implementing Nepad, the development partnership which aims to raise the quality of government in Africa and thus attract foreign investment.

There is pressure from the UN, campaigning organisations and G8 governments like those of Britain and France for the rich countries to give higher priority to tackling poverty - notably through a big increase in foreign aid.

Perhaps to increase the focus on development issues and the pressure for change, France has organised an enlarged dialogue at the summit between the G8 and 12 so-called emerging countries including China, India, Brazil and several Arab and African states.

It looks like Mr Chirac's multi-polar world in action.