World leaders descended on Toronto on Thursday for three days of summits among the Group of Eight (G8) leading industrialised nations and the Group of 20 (G20) top world economies.
The G8 summit on Friday and Saturday is expected to focus on development and security issues. The G20 summit, on Saturday evening and Sunday, is to deal with economic and financial reform.
"The European Union's message for the two summits here in Canada is clear: we must not allow the resolve for global, coordinated action to weaken," the president of the EU's executive, Jose Manuel Barroso, told journalists in Toronto.
Barroso and the president of the council of EU member states, Herman Van Rompuy, arrived in Toronto in the early afternoon.
The presidents of France, Russia and the US, the prime ministers of Britain, Japan and Italy and the chancellor of Germany all joined them later in the day.
Friday's G8 summit, set in the resort of Deerhurst, some 300 km north of Toronto, is expected to focus on development aid in general, and a Canadian call for increased action to reduce child and maternal mortality in poor states in particular.
G8 members have pledged to boost their aid to poor states massively by 2015 as part of the Millennium Development Goals (MDGs), but are billions of dollars short of their targets.
"I would like to see a strong signal by G8 leaders on how to speed up the pace on achieving the MDGs ... The contribution of the EU and its member states ... will be substantial," Barroso said.
Canada is a member of the G8 and G20, and Prime Minister Stephen Harper is chairing both events. He has labelled the summit an "accountability" meeting.
But earlier this month, a leaked draft summit communique failed to mention earlier G8 aid commitments. The glaring omission was allegedly because of lobbying from France and Italy, which lag far behind in meeting their aid targets for this year.
G8 leaders are also tipped to debate relations with developing powers such as China and global flashpoints such as Afghanistan, Iran, the Middle East and the Korean Peninsula.
Van Rompuy on Thursday appeared to issue China a veiled warning on its trade and business policy, which EU officials see as skewing opportunities in favour of Chinese firms.
"It cannot be that some countries are benefiting from international trade, but at the same time, rules on investment and intellectual property are manipulated," Van Rompuy said.
On Saturday, the G8 leaders are to be joined by their counterparts from Argentina, Australia, Brazil, China, India, Indonesia, Mexico, Saudi Arabia, South Africa, South Korea, Spain and Turkey.
Their discussions, in Toronto, are set to focus on the effects of the global financial and economic crisis and their efforts to overcome it.
Ahead of the talks, divisions emerged between European states, which have already begun slashing their crisis spending, and the US, which is urging G20 members not to cut back too soon.
Europe's cuts are "in order to save economic growth in the medium term, because if we don't take action to reduce our deficits, then we will really suffer from low and slow economic growth", Van Rompuy said.
Barroso also defended the policy, pointing out that "budgets in Europe this year will still be expansionary ... What we are suggesting for Europe is to start the exit strategy, and 2011 should be that date."
The G20 summit is also expected to debate calls for a worldwide levy on banks and a tax on financial transactions, and to discuss policy on global warming.
Ahead of the meeting, worldwide conservation group WWF urged the G8 to live up to earlier promises to donate $30 billion to poor states over the next three years to help fight climate change.
"The real measure of success for the G8 will be showing leadership on the fast-track finance commitments ... to support low-carbon development and climate adaptation in developing countries," WWF's top climate campaigner, Kim Carstensen, said in a statement.