U.S. Sen. Rand Paul has indicated he'll vote in favor of a resolution seeking to block President Donald Trump's national emergency declaration, giving Senate opponents enough votes to send the resolution to Trump's desk.

During a speech Saturday night in Bowling Green, Paul, R-Ky., said he "can’t vote to give extra-Constitutional powers to the president," according to the Bowling Green Daily News.

“I can’t vote to give the president the power to spend money that hasn’t been appropriated by Congress,” Paul said, as reported by the Bowling Green Daily News. “We may want more money for border security, but Congress didn’t authorize it. If we take away those checks and balances, it’s a dangerous thing.”

A spokesperson for Paul could not be immediately reached Sunday afternoon.

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Trump declared an emergency in February after Congress sent him a bipartisan funding bill that didn't include his $5.7 billion demand for a wall along the U.S.-Mexico border.

In declaring an emergency, the president is able to free up billions from other sources to pay for the barrier, which he claims is necessary to reduce the flow of drugs and gang members into the country.

Last week, the U.S. House of Representatives voted 245-182 in support of the resolution blocking Trump's declaration. Thirteen Republicans joined all Democrats in backing the measure.

Paul joins Republican Sens. Susan Collins of Maine, Lisa Murkowski of Alaska and Thom Tillis of North Carolina, who have all said they'll vote against the national emergency declaration.

Related:Kentucky Republican backs resolution to block emergency declaration

The resolution needs 51 votes to pass.

Assuming all the Senate's 47 Democrats and their independent allies vote against Trump, opponents would have the votes needed.

However, Trump is expected to veto the resolution, which would mark the first veto of his presidency.

This story may be updated.

Associated Press and USA TODAY contributed reporting. Reporter Matthew Glowicki can be reached at 502-582-4989 or mglowicki@courier-journal.com. Support strong local journalism by subscribing today: courier-journal.com/mattg.