WASHINGTON — The Federal Reserve, meeting at a time of heightened uncertainty, is expected to provide further support for a slumping U.S. economy. But there is no consensus over what form the added support will take.

Some private economists believe the Fed will launch another round of bond buying in an effort to drive long-term interest rates even lower. The aim would be to spur more borrowing, spending and economic growth.

At the very least, many economists believe the Fed will stress its readiness to do more should the economy weaken further.