US efforts to portray America's strong growth as a pattern for the global economy hit resistance at the Group of Eight summit among European allies who fear high oil prices and terrorism.
As G8 leaders wrapped up a three-day summit dominated by how to steer Iraq into a better future, French President Jacques Chirac again cautioned that big US trade and budget deficits threatened to unbalance the global economy.
President George W. Bush had earlier told fellow G8 leaders the US economy was performing at its strongest in decades, US officials said, partly due to tax cuts and reforms that could be an example to lagging Europe.
But some European leaders raised worries that were a surprise, US officials said.
"A number of people - what we hadn't been expecting - raised the issue of terrorism and how terrorism was a risk to the global economy and to global growth," the US official said in an interview. The official said that worry centered on "increased uncertainty" stemming from terror fears.
A closing summary of the G8 meeting, issued by the White House, was short on analysis of economic conditions, saying only that members "welcomed the increasing strength of the global economy" and that they needed to take advantage of it to press ahead with reforms to accelerate growth.
But Mr Chirac said at a press conference that US deficits, which have soared since the Bush administration took power in 2000, were among several risks to sustained expansion.
"In the context of growth, these worries are first the importance of the internal and external budget and financial deficits of the United States," Mr Chirac said. "They can at a given moment create imbalances and cause a landing that could be a little difficult, so we have to pay attention."
Evidently firing back at US calls for Europe to undertake market-based reforms that it said would further economic growth, Mr Chirac said no country was immune from the need for change.
"This situation of efforts to facilitate growth has brought us to become strongly aware of the need to make a certain number of reforms in each of the principal states - it's true for the United States, it's true for France and it's true for Germany," Mr Chirac said.
Some European concern seemed to reflect fear that failure to stabilise Iraq and defuse longstanding Middle East tensions could directly hurt efforts to keep recovery on track.
The G8 is comprised of the United States, Britain, France, Germany, Italy, Japan, Canada and Russia.
"Some focused on the risk of terrorism against oil directly but then some just focused on the risk of terrorism more broadly," the US official said. "It makes the world a less safe place, we need to battle terrorism and that's very important to sustain global growth."
German Chancellor Gerhard Schroeder fretted about oil prices and exchange-rate risk. The euro's strength could exacerbate Europe's sluggish growth by dampening demand for exports.
US officials have estimated that while the US economy will expand by around four and a half per cent this year, the 12-nation euro zone trails with anticipated growth of two per cent or less.
Amid a focus on African issues on Thursday, the G8 said it agreed to expand a debt relief programme for the world's poorest countries, many of which are in Africa.
The Highly Indebted Poor Countries initiative, or HIPC, that now includes nearly 40 countries that qualify for debt relief or forgiveness, was scheduled to expire in December.
The G8 extended the programme until December 2006 and agreed to increase its funding.
G8 leaders failed to clinch a deal on Iraqi debt, with France, Russia and Germany reluctant to go along with the other countries inclined to wipe out almost all of Iraq's sovereign obligations.
Mr Chirac said France favoured about a 50 per cent debt forgiveness, while US officials have indicated they would prefer numbers closer to 90 per cent.
Russian President Vladimir Putin told reporters it was clear something had to be done for Iraq but how much and how soon its debts would be reduced was unclear.