The Federal Reserve has unveiled a new set of unprecedented measures in its latest attempt to soothe markets that have been sent into tailspin by the coronavirus pandemic. In a plan unveiled Monday morning, the Fed said it will buy an unlimited amount of government-backed debt and announced a series of programs to give more security to large and small businesses. The central bank said in a statement: “While great uncertainty remains, it has become clear that our economy will face severe disruptions.... Aggressive efforts must be taken across the public and private sectors to limit the losses to jobs and incomes and to promote a swift recovery once the disruptions abate.” The statement went on to say that officials will buy bonds “in the amounts needed to support smooth market functioning.” The announcement makes clear the central bank is willing to go further than the $700 billion in purchases announced last week.