Fed's Williams says three rate hikes this year is his baseline view

San Francisco Federal Reserve Bank President John C. Williams said on Thursday he sees three interest rate increases for this year as his baseline scenario, but views four rate increases as also being appropriate if the U.S. economy gets an unexpected boost.

"There is potential for upside occurrences in the economy. One big question mark is if there is big fiscal stimulus or other changes in the outlook that we see the economy is doing better than we thought," said Williams, who was speaking on the sidelines of a forum held by the Bank of Korea in Seoul.