WASHINGTON — A Senate deal on border enforcement measures and Ukraine aid suffered a swift and total collapse Tuesday as Republicans withdrew support despite President Joe Biden urging Congress to “show some spine” and stand up to Donald Trump.

Just minutes after the Democratic president’s remarks at the White House, Senate Republican Leader Mitch McConnell emerged from a GOP luncheon at the Capitol and acknowledged that the deal was dead.

“It looks to me and to most of our members that we have no real chance here to make a law,” the Kentucky Republican told reporters.

Biden had engaged for months with Senate leaders on a carefully negotiated plan to pair policies intended to curb illegal crossings at the U.S.-Mexico border with $60 billion in wartime aid for Ukraine and would also have sent tens of billions of dollars more for Israel, other U.S. allies in Asia as well as aid for civilians in Gaza and Ukraine.

But after Republicans rejected the compromise, the president and Senate leaders are now stranded with no clear way to advance aid for Ukraine through Congress. They have run into a wall of opposition from conservatives — led by Trump — who reject the border proposal as insufficient and criticize Ukraine funding as wasteful.

Biden laid blame for the bill’s demise squarely on Trump — his likely Republican opponent in the November presidential election.

“For the last 24 hours he’s done nothing, I’m told, but reach out to Republicans in the House and the Senate and threaten them and try to intimidate them to vote against this proposal,” Biden said. “It looks like they’re caving. Frankly, they owe it to the American people to show some spine and do what they know to be right.”

During a floor speech Tuesday, Senate Majority Leader Chuck Schumer said: “After months of good-faith negotiations, after months of giving Republicans many of the things they asked for, Leader McConnell and the Republican conference are ready to kill the national security supplemental package even with border provisions they so fervently demand.”