SEOUL (Reuters) - South Korea's central bank chief said on Thursday the local economy is facing growing external uncertainties from the United States, China and increasing signs of trade protectionism.

At a global level, uncertainties include the Federal Reserve's policies, structural changes in the Chinese economy and Brexit, Bank of Korea governor Lee Ju-yeol said in a speech.

On the domestic front, low birth rates, aging population and household debt are structural problems faced by the economy, he added.

(Reporting by Cynthia Kim; Editing by Shri Navaratnam)