He also said he had "a series of encouraging conversations with countries planning to significantly reduce imports from Iran," to reinforce sanctions aimed at discouraging Iran's nuclear program.
"We are seeing very effective cooperation from our partners on the financial front to help ensure that their banks cease transactions with the Central Bank of Iran and that Iranian banks find it harder than ever to facilitate Iran's illicit nuclear activities or to help Iran evade sanctions," he said at a new conference.
Turning to the U.S. economy, Geithner said, "this is an important year for financial reform in the United States, where we expect to have the major foundations of our reform in place by the end of 2012."
While noting that the U.S. has made progress in some sectors on economic recovery, "even with this progress, however, the damage inflicted by the crisis will still take some time to repair. Unemployment, while falling, is still very high. And the housing market remains weak."
Lagarde, the IMF head, said some of the G-20 countries voiced complaints over draft U.S. financial regulations that would prohibit banks from trading for their own profit.
Lagarde also noted "the global economy is not out of the danger zone," adding that the recent run-up in oil prices represented a risk to recovery.
"We are obviously concerned about it," she said. "It has downside effects and risks for developed economies ... it has major consequences for developing countries."