A federal judge has ordered Argentina to pay holders of defaulted bonds, including Paul Singer’s Elliott Management, immediately, a blow to the country’s efforts to overcome a 2002 debt crisis that has raised fears of another default.

In a ruling Wednesday, Judge Thomas Griesa lifted a previous order stalling payments to so-called holdout investors who refused to take part in two swaps of defaulted debt.

Argentina’s president, Cristina Fernandez, has said her government will not pay “one dollar,” and Griesa’s ruling cited threats by Argentina’s leaders to defy his rulings in the decade-old dispute.