Federal Reserve Chairman Jerome Powell said the U.S. central bank will be patient about future interest rate increases as it watches to see how the U.S economy develops.

"We have the ability to be patient and watch patiently and carefully as we watch the economy evolve," Powell said during a conference at the Economic Club in Washington, D.C.

The central bank raised benchmark interest rates four times in 2018 and has indicated it may raise rates twice in 2019.

The core economy is "doing quite nicely," Powell said, while noting that he and other officials at the central bank were monitoring financial markets since they appear to be signaling greater concern about a looming slowdown or even a recession.  

"We see the financial markets expressing a view about the concern about downside risks associated with global growth and with trade," he said. 

Powell also said he isn't bothered by criticism from President Donald Trump, who once said hiring Powell was his one of his worst mistakes. Powell said he hasn't been asked to meet with the president over the matter, though he said he would be open to meeting with Trump.

The U.S. government shutdown, now in its 20th day, could hamper Fed officials' ability to gauge the economy if it lasts much longer, Powell said. The Commerce Department, which is affected by the shutdown, produces crucial economic data that Fed officials routinely examine. 

"We would have a less clear picture of the economy if it were to go on much longer," Powell said.