WASHINGTON — Senate Republicans blocked a bipartisan border package Wednesday, scuttling months of negotiations with Democrats on legislation intended to cut back record numbers of illegal border crossings.

Many Republicans said the election-year compromise wasn’t enough, even as supporters of the bill insisted it was the best possible in divided government.

The 49-50 vote, far short of the 60 ayes needed to take up the bill, came after most Republicans said they would vote against the legislation, which also includes $60 billion in wartime aid to Ukraine and $14 billion for Israel and was backed by President Joe Biden. GOP lawmakers had insisted that the money for conflicts abroad be paired with help for the U.S. border.

Forcing the showdown with Republicans, Senate Majority Leader Chuck Schumer said earlier that he would try to salvage the wartime funding, and would next push ahead on a crucial test vote for tens of billions of dollars for Kyiv, Israel and other U.S. allies — a modified package with the border portion stripped out.

The bipartisan group of senators who negotiated the compromise for the last four months said it was a missed opportunity to try and make some progress toward one of the most intractable issues in American politics.

In a speech on the Senate floor just before the vote, Republican Sen. James Lankford of Oklahoma said that it was a chance for the Senate to decide “if we’re going to do nothing, or something.”

“It’s an issue that’s bedevilled, quite frankly, this body for decades,” Lankford said. “It’s been three decades since we’ve passed anything into law to be able to change border security.”

Independent Sen. Kyrsten Sinema of Arizona blamed Republicans for not giving the bill a chance.

“Finally, it seemed, we had the opportunity to solve the nightmare my state has lived for over 40 years,” she said.

Four Republicans voted to move forward with the legislation and six Democrats voted against it, some of whom said the border compromise went too far.

It is unclear if enough Republicans will vote to move ahead with the standalone legislation for the wartime aid, which also would need 60 votes in the 51-49 Senate. If it did pass, it would still take days for the Senate to reach a final vote.

As some Republicans have grown skeptical of sending money to Ukraine in its war with Russia, Schumer said that “history will cast a permanent and shameful shadow” on those who attempt to block it.

“Will the Senate stand up to brutish thugs like Vladimir Putin and reassure our friends abroad that America will never abandon them in the hour of need?” Schumer asked as he opened the Senate.

The roughly $60 billion in Ukraine aid has been stalled in Congress for months because of growing opposition from hardline conservatives in the House and Senate who criticize it as wasteful and demand an exit strategy for the war.

“We still need to secure America’s borders before sending another dime overseas,” Republican Sen. Mike Lee of Utah wrote in a post on X.

The impasse means that the U.S. has halted arms shipments to Kyiv at a crucial point in the nearly two-year-old conflict, leaving Ukrainian soldiers without ample ammunition and missiles as Russian President Putin has mounted relentless attacks.

Ukraine’s cause still enjoys support from many Senate Republicans, including GOP leader Mitch McConnell, but the question vexing lawmakers has always been how to craft a package that could clear the Republican-controlled House.

A pairing of border policies and aid for allies — first proposed by Republicans — was intended to help squeeze the package through the House where archconservatives hold control. But GOP senators — some within minutes of the bill’s release Sunday — rejected the compromise as election-year politics.