Federal Reserve Chairman Jerome Powell expressed confidence in U.S. economic strength Wednesday and said markets will have to get used to the idea that the central bank could raise rates at any time starting in 2019.

During a question-and-answer session in Dallas, Powell conceded that the global economy is not growing at the same pace it was last year. But he said overall the domestic picture looks good. He described the global picture as a "gradual chipping away" at the pace of growth but said it is "not a terrible slowdown."

"I'm very happy about the state of the economy now," he said in an interview with Dallas Fed President Robert Kaplan. "Our policy is part of the reason why our economy is in such a good place right now."

That confidence has translated into a commitment by the policymaking Federal Open Market Committee to continue to increase short-term interest rates in a gradual but steady manner. The committee has approved three quarter-point increases this year and is expected to go through with a fourth in December.

Powell noted potential headwinds to growth, including slowness in housing and the potential that fiscal stimulus through tax cuts could wear off in another year or so.

Powell has faced some criticism for the Fed's policy. President Donald Trump has been vocal in his belief that the central bank's interest rate policy is the biggest threat to the growth seen during his administration.

For his part, Powell has refused to be drawn into a public debate with the president, maintaining that the Fed is independent and will continue to do what it thinks is best to maintain economic growth while keeping inflation under control and ensuring financial stability.

"We have a very important job that Congress has assigned us: Serve the public," he said. "That's our sole focus. We don't try to control things we don't control. We try to control the controllable. We're just trying to do our jobs, and we're doing fine."

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