The U.S. economy is running at a fast enough pace to justify continued interest rate increases, Federal Reserve Chairman Jerome Powell said Tuesday.

Powell is delivering his semiannual testimony to Congress this week, starting with an appearance Tuesday before the Senate Committee on Banking, Housing and Urban Affairs.

In remarks he provided ahead of a question-and-answer session, Powell painted a largely positive picture of the economy, which he said is expanding at an increasing pace and is being boosted by aggressive fiscal policy on Capitol Hill.

"Overall, we see the risk of the economy unexpectedly weakening as roughly balanced with the possibility of the economy growing faster than we currently anticipate," Powell said.

"The unemployment rate is low and expected to fall further. Americans who want jobs have a good chance of finding them," he added.

Powell spoke as the central bank is in the process of gradually raising interest rates. The policymaking Federal Open Market Committee has hiked the Fed's benchmark rate twice this year in quarter-point increments, and is expected to approve two more increases before the end of the year.