U.S. economy in the short term

In an official statement to the International Monetary Fund, Geithner also discussed the need to both support the U.S. economy in the short term and take steps to lower the nation's long-term deficits.

But his strongest comments were directed at Europe, where the specter of a default by the Greek government has upset financial markets around the world. The nation's long-standing debt problems are threatening to spill over into the European banking system, with possible repercussions for the fragile U.S. economy.

While he praised the actions European leaders have taken so far, Geithner said more needs to be done to create a "firewall against further contagion.