President Trump and Senate Republicans are bracing for an intra-party showdown Thursday as lawmakers are likely to block President Trump's border emergency declaration, likely forcing the president to use his veto powers for the first time.

The declaration was an effort by Trump to steer an extra $3.6 billion to build the border wall.

TRUMP SCUTTLES DEAL THAT WOULD AVOID SENATE REBUKE

Due to the small Republican majority in the Senate -- 53-47 -- it takes only four Republicans to vote in favor of the bill to block the declaration. Behind the scenes, Trump invited some Senate Republicans to the White House on Wednesday to talk about trade, but the conversation quickly turned towards their supposed vote against the president.

“He would like for us to vote against the [resolution]. But he understands and respects that senators may have different opinions,” Tennessee Republican Sen. Lamar Alexander, who reportedly hasn’t yet decided how he will vote on the resolution, told Politico. “There’s a border crisis and we have to deal with it. But I still have my constitutional concern.”

“He said that he wanted us to vote with him but understood if we didn't,” another Republican senator told the outlet.

PENCE URGES REPUBLICANS TO BACK NATIONAL EMERGENCY DECLARATION: IT'S 'WHAT THE AMERICAN PEOPLE WANT'

Trump tweeted Thursday that he's prepared to veto if necessary.

Vice President Mike Pence, meanwhile, urged Republicans to support the national emergency declaration in an interview set to air on “Fox & Friends” Thursday morning.

“A vote against the president's national emergency declaration is a vote to deny the humanitarian and security crisis that's happening at our southern border. So we're urging every member of the Senate set politics aside to recognize that we have a crisis,” he told "Fox & Friends’" Pete Hegseth.

Yet the passage of the anti-Trump resolution was effectively secured on Wednesday after the talks between the senators and the White House collapsed on Wednesday following a failure to reach a compromise on distinct legislation that would limit presidents’ powers to declare emergencies in the future.

Some Senators reportedly expressed willingness to back Trump’s declaration and please their constituents in the exchange of the measure curbing the expansion of presidential authority, a bill spearheaded by Utah Sen. Mike Lee.

Lee later issued a statement affirming his vote for the resolution that blocks Trump’s emergency declaration. “Congress has been giving far too much legislative power to the executive branch,” he said.

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The other Republican senators who have said they will vote to block Trump's border emergency are Thom Tillis of North Carolina, Susan Collins of Maine, Lisa Murkowski of Alaska and Kentucky's Rand Paul.

The Associated Press contributed to this report.