US Treasury Secretary Paul O' Neill has promised to help Argentina resolve its differences with the International Monetary Fund.

Earlier Argentina's president had told him that Argentina needed urgent aid to help it overcome its financial crisis.

Mr O'Neill - on the last leg of a tour of the region - failed to offer any fresh aid to crisis-hit Argentina.

But the US financial chief said he hoped a deal between the IMF and Argentina would be completed "very quickly".

Argentina, which descended into economic and political crisis in December, is negotiating with the IMF to roll over its debts.

Mr O' Neill offered to give the country "technical advice" and said that the US was "glad to work through the international financial institutions to support nations that support sustainable growth-creating policies".

Others outside the US treasury secretary's hotel burned his photo with the caption 'O'Neill and the IMF get out'

The BBC's Tom Gibb

Argentina's president, Eduardo Duhalde, made the plea for help during a meeting on Tuesday night with Mr O'Neill.

Mr O'Neill said that the US government, more than anybody else, wanted to see the Argentine people overcome this critical situation, the presidential spokesman said.

Mr Duhalde's comments appear to reflect the government's frustration at failures in accessing fresh loans despite months of negotiations with the IMF.

Hard work

Chanting protesters burned photos of Mr O'Neill and lit flares outside his hotel as he gave a speech in support of Argentina's economic policy.

"We expect nothing from this visit, except probably an even stronger submission of our government to the United States and the IMF," said Mariano Sanchez, one of the organisers of the protest.

We want Argentina to succeed. We are anxious for them to succeed

Paul O'Neill US Treasury Secretary

The BBC's Tom Gibb in Buenos Aires said that some 1,500 people marched past the presidential palace.

"Others outside the US treasury secretary's hotel burned his photo with the caption 'O'Neill and the IMF get out'," he added.

Latin tour

Mr O'Neill has already visited Brazil and Uruguay.

Brazil, which has the largest economy in the region, is being buffeted by fears that it could default on a $250bn public debt if a left-winger wins the October presidential election.

Meanwhile Uruguay seemed on the brink of following Argentina into deep recession.

The country was forced to close its banks last week - only re-opening them on Monday - to head off a dangerous depletion of funds.

Mr O'Neill offered words of support for both countries.

In Uruguay on Tuesday, he praised the government's "sound economic policies" that it adopted in the face of the country's financial crisis.

Argentina's woe

Argentina's economy collapsed after the IMF suspended $22bn in aid because the government failed to control overspending.

The country has already defaulted on its privately held debt.

Mr O'Neill said that Mr Duhalde had not mentioned the debt rollover during their meeting.

The US is the largest and most influential shareholder of the IMF so Mr O'Neill's support for any debt rollover is seen as crucial.

Argentina owes the IMF $7bn in debt repayments, and the fund has already agreed to postpone payment in July of $985m.