WASHINGTON >> Senate Republicans today blocked the advance of a $110 billion package of wartime funding for Ukraine and Israel as well as other national security priorities as they tried to force President Joe Biden to include changes to U.S. border policy.

The vote, a 49-51 tally that fell short of the Senate’s 60-vote threshold for moving ahead, came just hours after Biden said it was “stunning” that Congress has not yet approved tens of billions of dollars in military and economic assistance for Ukraine. His administration warned of dire consequences for Kyiv — and a “gift” to Russia’s Vladimir Putin — if lawmakers don’t act.

Speaking at the White House, Biden said Republicans who are insisting on border policy changes as a condition for voting for the aid “are playing chicken with our national security,” even as he expressed openness to some policy changes.

“Republicans in Congress are willing to give Putin the greatest gift he could hope for,” Biden said, saying American credibility was on the line both with other would-be aggressors and with its allies. “Any disruption in our ability to supply Ukraine clearly strengthens Putin’s position.”

“If we don’t support Ukraine, what is the rest of the world going to do?” he added.

Biden’s address comes hours after he huddled with Ukrainian President Volodymyr Zelenskyy and leaders of the Group of Seven advanced democracies, which have staunchly supported Ukraine against Russia’s ongoing invasion.

Biden has asked Congress for nearly $106 billion to fund the wars in Ukraine, Israel and other security needs, but has faced stiff resistance on Capitol Hill. Some Republicans have grown tired of providing support to Ukraine after the U.S. has already sent $111 billion, and other GOP lawmakers are insisting on stiff changes to U.S. border policy as a condition of voting for the measure.

Biden said he supports more funding for border security. “I am willing to make significant compromises on the border,” he said. “We need to fix the broken border system. It is broken.” He added that he’s “ready to change policy as well,” but accused Republicans of wanting a political issue more than bipartisan compromise.

“Republicans think they get everything they want without any bipartisan compromise,” Biden said. “Now they’re willing to literally kneecap Ukraine on the battlefield and damage our national security in the process.”

But Biden has not publicly said what policy changes he would embrace.

The White House has sent increasingly sharp warnings to lawmakers of what would happen if they don’t approve the measure before the end of the year, saying Ukraine’s military would be stalled, or worse.

“We’re the reason Putin hasn’t totally overrun Ukraine,” Biden said.

On Capitol Hill, Senate Democrats tried to advance the aid package, but the legislation had no way forward as Republicans vowed to withhold support unless it includes changes to U.S. border policy. Negotiations over the legislation all but collapsed this week.

Senate Majority Leader Chuck Schumer called the result “a sad night in the history of the Senate and our country.”

Senate Republican Leader Mitch McConnell, who has been an ardent supporter of aid to Ukraine, told fellow Republicans to vote against the security package advancing.

“Legislation that doesn’t include policy changes to secure our borders will not pass the Senate,” McConnell said in a speech on the Senate floor earlier today. “The situation unfolding at our southern border on President Biden’s watch is a crisis of historic proportions.”

Republicans pointed to the record numbers of migrants crossing the southern border and argued it posed a security threat because border authorities cannot adequately screen them. But their demand that Congress pass significant changes to U.S. border policy interjects into the debate an issue that lawmakers have grappled over for decades with little success.

By holding the test vote, Schumer dared his Republican counterparts to vote against the cause of Ukraine funding that most have previously supported. He said in a speech the Senate is facing a question that “goes to the actual preservation of Western and democratic values in the world.”

Democrats were also making their case through a series of events on Capitol Hill with Ukrainian officials, including the speaker of Ukraine’s parliament.

The pressure appeared to have little affect on the GOP’s stance. But senators expressed some hope that Biden’s remarks would revive the talks over border security policy.

“This kind of thorny, difficult problem is exactly what Joe Biden and Mitch McConnell have worked on before. And we could use their help and their leadership on this,” said Sen. Michael Bennet, D-Colo., one of the senators involved in negotiations over border policy.

As they look past the test vote, GOP senators have prepared a proposal for the bipartisan group in the talks. So far, senators have found some agreement on raising the initial standard for migrants to enter the asylum system but were stuck over placing limitations on humanitarian parole, a program that allows the executive branch to temporarily admit migrants.

“We’re clearly engaging in the negotiations, trying to be able to solve this,” said Sen. James Lankford, a Republican of Oklahoma who is involved in the talks.

But even if senators somehow find a way forward on the aid package, it still faces significant obstacles in the House. Hardline conservatives who control the chamber have vowed to block it unless it tacks to a broad set of hard-line border and immigration policies.

House Speaker Mike Johnson, already deeply skeptical of funding for Ukraine, has signaled he won’t support the aid package if it does not adhere to H.R. 2, a bill that would remake the U.S. immigration system with conservative priorities. It passed the House on a party-line vote in May, but has been rejected by Senate Democrats.

Meanwhile, the U.S. announced a $175 million package of military aid to Ukraine today, including guided missiles for the High Mobility Artillery Rocket Systems (HIMARS), anti-armor systems and high-speed anti-radiation missiles, according to U.S. officials.

Brig. Gen. Pat Ryder, the Pentagon press secretary, said Tuesday there is about $1.1 billion left in funding to replenish U.S. military stockpiles for weapons and equipment sent to Ukraine. And he said there is roughly $4.8 billion in drawdown authority still available.