WASHINGTON - The International Monetary Fund (IMF) on Friday said more stimulus spending might be needed to aid a slow US economic recovery, wading into a toughly-fought political debate in Washington.

Warning that the "economic recovery has been slow by historical standards" and that "the outlook remains uncertain," the IMF's directors said more stimulus spending might be needed.

"Further decisive action is needed to achieve stable medium-term growth and limit risks of adverse international spillovers."