NEW YORK, May 23 (Reuters) - The possibility that Britons could vote to leave the European Union a week after a mid-June Federal Reserve decision on raising interest rates will play a role in that decision, but the U.S. central bank has options to adjust, a top Fed official said on Monday.

“It’s a factor in the decision for June obviously because you have an event right after, and we can obviously hold off until July if we wanted,” San Francisco Fed President John Williams, speaking to reporters here, said of raising rates at the next two policy meeting.

“But of course we could also make a decision to raise rates at a meeting and if later on economic conditions for the U.S. change, we can always move interest rates back down.”