WASHINGTON — Federal Reserve Chairman Ben Bernanke said this morning the stimulus package being crafted by President-elect Barack Obama and Congress could provide a "significant boost" to the sinking economy.

But he warned that such a recovery won't last unless other steps are taken to stabilize the shaky financial system.

Although Bernanke has previously endorsed the notion for a fresh round of government stimulus to lift the country out of a recession, it marked the first time the Fed chief has referenced the roughly $800 billion recovery plan now being worked on by Obama, who takes office next week.

Bernanke, who didn't weigh in on the details of the package, made clear that such a recovery plan was needed as part of a broader, multipronged government response to combat the worst financial crisis to hit the global economy since the 1930s.

"The incoming administration and the Congress are currently discussing a substantial fiscal package that, if enacted, could provide a significant boost to economic activity," Bernanke said at the London School of Economics.

"In my view, however, fiscal actions are unlikely to promote a lasting recovery unless they are accompanied by strong measures to further stabilize and strengthen the financial system," he warned.

To help with that, the Fed is loaning out billions to financial companies and buying mounds of companies' debt to help bust through the debilitating credit clog. And the Treasury Department is overseeing a $700 financial bailout program that has pledged to inject $250 billion into banks in return for partial government ownership.