But even as he maintains a frenetic pace — unveiling plans, testifying before Congress and negotiating new bailouts with the likes of Citigroup, General Motors and the American International Group — there are signs that events are getting ahead of him…

Treasury officials are also still scrambling to decide details of their plan to buy up as much as $1 trillion in toxic assets from the nation’s banks, one month after being widely criticized for presenting a plan that lacked any specifics on how it would work.

Analysts say it is far too early to know if Mr. Geithner and his team will be effective. But some worry that political and financial constraints have made them reluctant to grapple with the full magnitude of the crisis.