WASHINGTON >> President Joe Biden today urged Congress to “show some spine” and stand up to Donald Trump even as a Senate deal on border enforcement measures and Ukraine aid was rapidly collapsing.

The Democratic president has engaged for months with Senate leaders to form a bipartisan plan that pairs policies intended to curb illegal crossings at the U.S. border with Mexico with $60 billion in wartime aid for Ukraine, as well as tens of billions of dollars more for Israel, other U.S. allies in Asia, the U.S. immigration system and humanitarian aid for civilians in Gaza and Ukraine. But within days of an agreement being reached, Senate Republicans have backed away from the package, stranding Biden with no clear way to advance aid for Ukraine through Congress.

“If the bill fails, I want to be absolutely clear about something, the American people are going to know why it failed. I’ll be taking this issue to the country,” Biden said, adding that Trump, the likely Republican presidential nominee is to blame.

Biden, along with the Senate’s top Democrat, Sen. Chuck Schumer, and top Republican, Sen. Mitch McConnell, have run into a wall of opposition from conservatives — led by Trump — who rejected the border proposal as insufficient.

Schumer, from New York, cast today as a “gloomy day here in the United States Senate” during a floor speech in which he scolded Republicans for backing away from the deal. He offered to delay a key test vote on the package until Thursday, but still dared them to vote against border security — an issue they have long championed.

“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,” Schumer said.

The White House has worked for months with senators on the carefully negotiated compromise in hopes that it would unlock Republican votes for the Ukraine aid in the House — where scores of GOP lawmakers have come out against funding Kyiv’s fight against Russia. The impasse threatens a cornerstone of Biden foreign policy: Halting Russian President Vladimir Putin’s advance into Europe.

The Pentagon is sending no more arms shipments to Kyiv just as the war — entering its third year — reaches a critical juncture. Ukraine is struggling with ammunition and personnel shortages while Russia is on the offensive, mounting relentless attacks.

The lack of a national security deal will loom large over Biden’s Friday meeting with German Chancellor Olaf Scholz. Biden plans to underscore to Scholz that he remains committed to providing Ukraine the funding it needs to continue to repel the nearly two-year old Russian invasion.

“I think he will make clear to Chancellor Scholz how much he personally wants to continue to support Ukraine, how hard Senate negotiators worked on both sides of the aisle to get at this final bill,” National Security Council spokesman John Kirby told reporters today. “And I think he will also … remind the chancellor that there is strong bipartisan support actually in both chambers.”

McConnell, from Kentucky, said in a floor speech that it was essential to assert American strength in Europe, the Middle East and Asia, yet also blamed Biden for not responding sooner to threats from rival powers.

“Either we confront challenges we face with clear strategy and firm resolve or we lose,” McConnell said. He made no mention of the need for border security — a piece of the national security package that he last year insisted on including.

Facing the prospect of Republicans voting against the package en masse, McConnell recommended to GOP senators on Monday they vote against the first procedural vote, according to two people familiar with the meeting who were not authorized to talk publicly about it and spoke anonymously.

The longtime Republican leader has not been able to convince his conference to warm to the compromises on border security after Trump, the likely Republican presidential nominee, excoriated it. Within hours of the bill’s release Sunday, House Speaker Mike Johnson said he would not support it, and even GOP senators who had been supportive of the border policies under discussion came out against the bill today.

The border proposal represents one of the most conservative and comprehensive proposals in decades to emerge from a bipartisan negotiation in Congress. It would seek to tamp down the historic number of illegal border crossings by making the asylum process tougher and faster. Presidential administrations would also be given authority to deny migrants from claiming asylum at the border if the number of migrants claiming asylum becomes unmanageable for authorities.

“We have a very conservative bipartisan border bill that fixes the problem at the border,” said Connecticut Sen. Chris Murphy, who negotiated the bill for Democrats. “And it’s time for the country to see where people stand on that.”

But Republicans have largely heeded the wishes of Trump to reject the bill because it would show that Biden could act to address problems at the border, which is seen as one of his largest vulnerabilities in his reelection campaign.

“The politics of this were a big factor,” said Sen. John Cornyn, a Texas Republican. “When the speaker said basically the Senate bill is dead on arrival. And then President Trump weighs in and discourages Republicans from voting for it.”

Cornyn said he would support a move to jettison the border measures from the package and try to advance the aid for U.S. allies on their own.

But that idea also faces resistance in the Republican-controlled House, where Johnson has also left any support for Ukraine aid in doubt.

When asked about wartime aid for Ukraine and Israel today, he told reporters, “We have to deal with these measures and these issues independently and separately.”

The House was scheduled to vote on a $17.6 billion package of military aid for Israel, but hardline conservatives have signaled opposition because the funding would not be offset with budget cuts in other areas.

House Democratic leaders also said they would not support the bill for Israel. In a letter to Democrats, House Democratic Leader Hakeem Jeffries, along with Reps. Katherine Clark and Pete Aguilar, said the bill was not being offered “in good faith” and urged Democrats to hold out for a package that addresses Ukraine and allies in Asia.

“It is a nakedly obvious and cynical attempt by MAGA extremists to undermine the possibility of a comprehensive, bipartisan funding package that addresses America’s national security challenges in the Middle East, Ukraine, the Indo-Pacific region and throughout the world,” they said.

Meanwhile, a group of nine U.S. diplomats to Indo-Pacific countries has written to U.S. lawmakers urging them to pass the supplemental for the sake of American credibility abroad.

“Many countries in the Indo-Pacific are intently focused on the conflicts in Ukraine and the Middle East,” the diplomats wrote in the letter that was delivered to lawmakers Monday. “With Russia’s growing strategic partnership with the People’s Republic of China and military support from Iran and North Korea, our support for Ukraine — or the potential termination of that support at such a decisive moment — will fundamentally affect not just Ukraine, but other strategic theaters as well.”