A bipartisan group of senators have reached a deal that would force the federal government to shut down the border for migrants crossing illegally during surges and expedite the asylum process, sources familiar with the negotiations tell Axios.

Why it matters: The details of the deal come after days of senators scrambling to keep the deal alive, Speaker Mike Johnson (R-La.), threatening that it would be "dead on arrival" in the House, and President Biden promising to use the expanded authority to shut down the border "the day I sign the bill into law."

• It is unclear whether the plan will satisfy the conservatives demanding significant border policy changes, especially with Donald Trump centering much of his 2024 campaign around “Biden's border crisis.”
• Its fate is also linked to the prospects of unlocking billions of dollars in military aid for Ukraine and Israel, which Republicans have held up while pushing for a border package.
• Sens. James Lankford (R-Okla.), Kyrsten Sinema (I-Ariz.) and Chris Murphy (D-Conn.) have been working to strike a bipartisan deal for months.

The details: The agreement would automatically reject migrants and asylum seekers from crossing the border illegally once the daily average for border crossings surpasses 5,000 over a week or crossings surpass 8,500 on a single day, sources tell Axios.

• The Department of Homeland Security would also have the option of using the authority even earlier — once crossings surpass a daily average of 4,000 over the course of a week.
• Migrants could be granted exceptions for humanitarian reasons. There would also be harsher penalties for those who attempt to illegally cross the border multiple times, banning them from entering the U.S. after two attempts.
• Title 42 notably led to an increase in repeat crossers.
• CNN first reported on the details of the deal.

Zoom in: When the border is closed, migrants would only be able to seek asylum at legal ports of entry, where officials would be required to process a minimum number of asylum cases, according to one source.

• The restrictions would not lift until border crossings remained far below the average daily threshold for two weeks, according to another source.
• Another measure would limit the use of parole to release migrants into the U.S. though the specifics remain unclear.
• The plan would also expedite the asylum process, requiring cases to be considered within six months. The process often takes years, currently.

What they're saying: "Let's be clear. What's been negotiated would – if passed into law – be the toughest and fairest set of reforms to secure the border we've ever had in our country," Biden said in a statement issued Friday evening.

• "It would give me, as President, a new emergency authority to shut down the border when it becomes overwhelmed. And if given that authority, I would use it the day I sign the bill into law."
• "If you're serious about the border crisis, pass a bipartisan bill and I will sign it," he stated.

By the numbers: One source familiar with the negotiations said that under these provisions, the U.S.-Mexico border would have been closed to illegal border crossers for the past four months.

• There were more than 300,000 encounters between border officials and migrants crossing the southern border last month — including nearly 250,000 who illegally crossed the border.