By Michael S. Derby

NEW YORK The three newest Federal Reserve governors, including Vice Chair Philip Jefferson, have told a U.S. senator it's unclear how much further the central bank's balance sheet wind-down process will run, but said it is likely the process faces no imminent end.

"The size of our balance sheet ultimately will depend on the public's demand for our liabilities, particularly currency and reserves and we cannot specify in advance what that demand will be, hence we are not targeting any particular dollar value for our balance sheet," Jefferson wrote in a letter to Republican U.S. Senator Rick Scott.

"Under plausible assumptions the size of the balance sheet could decline considerably further before reserves reach the level consistent with the ample reserves operating framework," Jefferson wrote in response to a series of questions from Scott about the roughly $8 trillion balance sheet. Jefferson added that the Fed will adjust its efforts to respond to economic and financial developments.

Jefferson was responding to letters Scott sent to him and Fed Governors Lisa Cook and Adriana Kugler in September, and his comments mirrored the responses of his two colleagues.

All three replies were dated Nov. 14 and were provided to Reuters by Scott's office. The senator's office did not comment on what Scott, a fierce critic of the Fed's large-scale asset purchases, thought of the letters.

Jefferson was confirmed as the Fed's second-in-command this year after having become a central bank governor in 2022. Cook was confirmed to a new term as a governor this year and Kugler joined the board this year.

(Reporting by Michael S. Derby; Editing by Dan Burns and Paul Simao)