"There are reasons for being concerned," the economist Olivier Blanchard told the Thursday edition of the newspaper in an interview.
He was responding to questions about measures in the United States to curb the deficit, after the rating agency Standard and Poor's decided to put US long-term debt on negative watch.
Blanchard said that "the United States lacks a credible plan, in the medium term, to reduce its budget deficits" and that although the speech by President Barack Obama, made on April 13, went in the right direction" any "concrete decisions had yet to be taken."
He said that the debate between the two parties (Republicans and Democrats) which ended on April 8 with a plan to save $39 billion (27 billion euros) was not enough."
He commented: "The ideological gulf between Democrats and Republicans on how to deal with the problem is enormous."