WASHINGTON — Senators on Sunday released a highly anticipated $118 billion package that pairs border enforcement policy with wartime aid for Ukraine, Israel and other U.S. allies, setting off a long-shot effort to push the bill through heavy skepticism from Republicans, including House Speaker Mike Johnson.

The proposal could be the best chance for President Joe Biden to resupply Ukraine with wartime aid — a major foreign policy goal that is shared with both the Senate’s top Democrat, Sen. Chuck Schumer, and top Republican, Sen. Mitch McConnell. The Senate was expected this week to hold a key test vote on the legislation, but it faces a wall of opposition from conservatives.

With Congress stalled on approving $60 billion in Ukraine aid, the U.S. has halted shipments of ammunition and missiles to Kyiv, leaving Ukrainian soldiers outgunned as they try to beat back Russia’s invasion.

Senators have been working for months on the carefully negotiated compromise intended to overcome opposition from conservatives who have tired of funding Ukraine’s fight. But the coming days will be a crucial test of whether congressional leaders can once again muscle their members to support the package designed to assert American strength — and commitment — around the world. They will also be balancing one of the most fraught issues in American politics — border and immigration legislation.

Biden said in a statement that the Senate proposal ”allows the United States to continue our vital work, together with partners all around the world, to stand up for Ukraine’s freedom and support its ability to defend itself against Russia’s aggression.”

And on the border, Biden said that the immigration system has been broken for too long, and it’s time to fix it. ”It will make our country safer, make our border more secure, treat people fairly and humanely while preserving legal immigration, consistent with our values as a nation,” Biden said.

The proposal would overhaul the asylum system at the border with faster and tougher enforcement, as well as give presidents new powers to immediately expel migrants if authorities become overwhelmed with the number of people applying for asylum. The new bill would also invest in U.S. defense manufacturing, send $14 billion in military aid to Israel, steer nearly $5 billion to allies in the Asia-Pacific, and provide humanitarian assistance to civilians caught in conflicts in Ukraine and Gaza.

In a call with reporters after releasing the legislation, Schumer said he has never worked so closely with McConnell. He called the bill a ”monumental step” toward strengthening national security at home and abroad.

Without the Ukraine aid, Schumer said, he believes Russian President Vladimir Putin ”could be rolling over Ukraine and even into Eastern Europe.”

McConnell said in a statement that the Senate must be ”prepared to act.”

”America’s sovereignty is being tested here at home, and our credibility is being tested by emboldened adversaries around the world,” McConnell said. ”The challenges we face will not resolve themselves, nor will our adversaries wait for America to muster the resolve to meet them.”

In a bid to overcome opposition from House Republicans, McConnell had insisted last year that border policy changes be included in the national security funding package. However, in an election-year shift on immigration, Biden and many Democrats have embraced the idea of strict border enforcement, while Donald Trump and his allies have criticized the proposed measures as insufficient.

Rep. Elise Stefanik of New York, the third-ranked House Republican and a close ally of Trump, quickly decried the bill as ”an absolute non-starter” that would incentivize illegal immigration.

Republicans have also been reluctant to give Biden a political win on an issue they see as one of his biggest vulnerabilities. They have argued that presidents already have enough authority to curb illegal border crossings — a stance that would ensure immigration remains a major issue in the presidential election. But at the same time, House Republicans have also pushed for their own, stricter version of border security legislation.

Johnson, a Republican of Louisiana, told NBC’s ”Meet the Press” on Sunday morning that he was unaware of the bill’s details, but thought the solution to border problems should be a House proposal of hardline immigration measures.

That bill, which passed the House last year without a single Democratic vote, currently has no chance of gaining the Democratic support it would need in the Senate. GOP senators also attempted to add it on to other legislation last year, but that effort only gained 46 votes.

”What we’re saying is you have to stem the flow,” Johnson said. He also made it clear that he — not Trump — would decide whether to bring the bill to the floor if it passes the Senate.

But in a further sign that Johnson is resistant to the Senate package, he indicated Saturday that the House will vote on a separate package of $17.6 billion of military aid for Israel — a move that allows House Republicans to show support for Israel apart from the Senate deal.

It is still unclear if the bill will pass in the Senate. Senate Republicans have been divided on the bill, with several in McConnell’s ranks arguing that it isn’t strong enough. Some quickly said they would vote against it.

”I will not support this deal,” said Sen. Marsha Blackburn, R-Tenn, after the legislation was released.

The proposal is aimed at gaining control of an asylum system that has been overwhelmed by historic numbers of migrants coming to the border.

Migrants who seek asylum, which provides protection for people facing persecution in their home countries, would face a tougher and faster process to having their claim evaluated. The standard in initial interviews would be raised, and many would receive those interviews within days of arriving at the border. Final decisions on their asylum claims would happen within months, rather than the often years-long wait that happens now. They would also be given work permits if they pass the initial screenings.

Sen. Kyrsten Sinema, an Arizona independent who negotiated the border proposal, told CBS’ ”Face the Nation” that the legislation would be ”the strongest solution to our border crisis in my lifetime.”

”America is and continues to be a bastion of hope for true asylum seekers,” she told reporters later. ”But it is not an open door for economic migrants. It has been, as we know, exploited dramatically by cartels in the last four to five years.”

If the number of illegal border crossings reaches above 5,000 daily for a five-day average, an expulsion authority would automatically kick in so that migrants who cross illegally are expelled without an opportunity to make an asylum claim. If the number reaches 4,000, presidential administrations would have the option of using the new authority. Under the proposal, migrants could still apply at ports of entry.

Biden, referencing the authority, has said he would use it to ”shut down the border” as soon as the bill is signed into law.

The bill would allot $20 billion to immigration enforcement, including the hiring of thousands of new officers to evaluate asylum claims and hundreds of Border Patrol agents, as well as funding local governments that have seen influxes of migrants.

Among Democrats, the tougher asylum standards have raised concern, especially from progressive and Hispanic lawmakers. Sen. Alex Padilla, a Democrat of California, said in a statement that the proposal would still cause ”more chaos at the border, not less.”

The $14 billion in the package intended for military support for Israel could also splinter Democratic votes. Sen. Bernie Sanders, an independent of Vermont, is pushing to strip $10 billion for offensive weaponry for Israel from the package while maintaining money for defensive systems.

Schumer said he would schedule a key test vote on the legislation Wednesday.