Federal Reserve Chair Janet Yellen did not comment on the U.S. economy or monetary policy in brief welcoming remarks to a community banking symposium on Wednesday.

It was Yellen's first public appearance since a health scare last week in Massachusetts in which she stumbled over her words and struggled to complete a nearly hour-long speech.

The Fed said at the time she suffered from dehydration after a long day, and was cleared by an emergency medical technician to proceed with a planned dinner that evening.

In opening remarks scheduled for delivery to a Conference of State Bank Supervisors gathering on community banking, Yellen said smaller banks were "essential" to the U.S. economy and said the Fed was working to tailor its oversight to make sure it is not overly burdensome for community banks.