Kentucky Sen. Rand Paul says he will send a $600,000 check to the U.S. Treasury, returning the part of his operating budget as a senator that was not spent.

Paul made the announcement at press conference in Kentucky on Wednesday. According to a press release from Paul’s office, the sum is over 20 percent of the total operating budget.

Last year, he returned $500,000 worth of unspent funds to the Treasury.

“I ran to stop the reckless spending, and I pledged to the people of Kentucky that I would work to keep their hard-earned money out of the hands of Washington bureaucrats whose irresponsible spending has threatened our country’s economic health,” Sen. Paul said.

The Republican senator and son of libertarian icon Ron Paul is considered a likely 2016 presidential contender.

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