The US Treasury Secretary Timothy Geithner has said Dominique Strauss-Kahn is "not in a position to run" the International Monetary Fund after his arrest over an alleged sexual assault.
Mr Geithner has said the IMF's executive board should designate an interim head.
The alleged assault on a maid happened at New York's luxury Sofitel hotel on May 14.
Mr Strauss-Kahn, who denies the claims, has been put on suicide watch in the city's Rikers Island prison.
As a precaution, guards are required to check on him every 15 to 30 minutes.