Robust US economic growth will likely continue into 2005, but authorities should cut the budget deficit to reduce the risk to growth, the IMF's managing director Rodrigo Rato said.
Mr Rato also said in an interview that the European Union's economy was performing below its potential, and called for measures to balance budgets to capitalise on its recovery.
"The growth in the United States is certainly robust, and I think that it's going to continue for the next part of this year and next year. But the macro-economic risk that's there should be addressed," Mr Rato said.
Speaking on a flight from Johannesburg to a poverty conference in the West African country of Burkina Faso, Mr Rato declined to give precise growth forecasts.
He said earlier this month he expects global growth to be slightly higher than the IMF's previous estimate of 4.6 per cent, but warned high oil prices could dampen the world economy.
He went on to say that the United States - which is facing another record budget deficit of $422 billion for the 2004 fiscal year - should reduce its fiscal stimulus, which he described as "extraordinary" in monetary and budget terms.
Mr Rato, who took the IMF helm three months ago, said Europe was underperforming both because of its macroeconomic background and because of structural reforms.
"...I think that both should be addressed, and I think that now is a good moment to address it because the recovery makes things easier to tackle. Europe should avoid the same mistakes it made in 1999, which was not to take advantage of the recovery to increase its budgetary balances," he said.
"This is a very important moment for the European Union to take advantage of the recovery and have a clear budgetary agenda to get sustainability and to help the macro-economic stability of the EU."