The White House said on Sunday it would this week propose radical reforms to public spending, an attempt to regain the initiative after a last-minute deal on Friday to avoid a federal government shutdown.

David Plouffe, a senior White House adviser, said Barack Obama, the president, would propose “significant debt reduction”, including looking at the federal Medicare and Social Security programmes, traditionally regarded as sacrosanct. “Every corner of the federal government has to be looked at,” Mr Plouffe said on Sunday, although he added that spending on investment and education would be protected whenever possible.

Congressional Republicans reacted with scorn to the announcement, saying Mr Obama had been dragged reluctantly into making the first round of cuts agreed on Friday, and was unlikely to have a clear plan for more.