U.S. House Speaker Mike Johnson led about 60 fellow Republicans in Congress on a visit Wednesday to the Mexican border to demand hard-line immigration policies in exchange for backing President Joe Biden's emergency wartime funding request for Ukraine. He expressed serious doubts about whether he would support a bipartisan compromise.

The trip to Eagle Pass, Texas, came as the Senate engages in delicate negotiations in hopes of striking a deal on border policies that could unlock Senate GOP support for Biden’s $110 billion package for Ukraine, Israel and other U.S. security priorities.

But Johnson, R-La., told The Associated Press during the border tour that he was holding firmly to the policies of a bill passed by House Republicans in May without a single Democratic vote. The bill, H.R. 2, would revive many of the policies pursued by former President Donald Trump, build more of the border wall and impose new restrictions on asylum seekers. Democrats called the legislation “cruel” and “anti-immigrant,” and Biden promised a veto.

“If it looks like H.R. 2, we'll talk about it,” Johnson said of any border legislation that emerges from the Senate.

With the number of illegal crossings into the United States topping 10,000 on several days last month, Eagle Pass has been at the center of Republican Gov. Greg Abbott’s Operation Lone Star, his nearly $10 billion initiative that has tested the federal government’s authority over immigration and elevated the political fight over the issue.

The GOP House members touted their event as the largest congressional border trip ever. They traveled in two large buses beneath an international bridge in Eagle Pass where just two weeks ago illegal crossings prompted a large federal response that included closing railroad traffic and creating a large field for processing migrants. By Wednesday, the field sat empty with only stakes in the ground and orange fencing.

At a news conference, Johnson suggested he could use a looming government funding deadline as further leverage.

“If President Biden wants a supplemental spending bill focused on national security, it better begin with defending America’s national security," he said. Johnson added: “We want to get the border closed and secured first."

Biden has expressed willingness to make policy compromises as the historic number of migrants crossing the border is an increasing challenge for his 2024 reelection campaign. Homeland Security Secretary Alejandro Mayorkas and White House staff have been involved in the Senate negotiations.

“We’ve got to do something," Biden told reporters Tuesday night. He said Congress should approve his national security proposal because it also includes money for managing the influx of migrants. "They ought to give me the money I need to protect the border,” he said.

Administration officials have criticized Johnson's trip as a political ploy that will do little to solve the problem. White House spokesperson Andrew Bates said Republicans were compromising national security by threatening to shut down the government and delaying approval of funding for additional border security.

“When they’re at the border, they’re going to see the magnitude of the problem and why we have said now for about three decades, their broken immigration system is in desperate need of legislative reform,” Mayorkas told CNN on Wednesday. “So we are focused on the solutions, and we hope that they will return to Washington and focus on the solutions as well.”

House Republicans also contend that Mayorkas' management of the border has amounted to a dereliction of his duties and they are moving ahead with rare impeachment proceedings against a Cabinet member, with a first committee hearing on the matter scheduled for next week. Mayorkas told MSNBC he would cooperate with an inquiry.

During parts of December, border crossings in Eagle Pass, as well as other locations, swamped the resources of Customs and Border Protection officials. Authorities closed cargo rail crossings in Eagle Pass and El Paso for five days and shut down border crossings in the Arizona city of Lukeville.

Authorities say the numbers of migrants eased over the December holidays as part of a seasonal pattern. The border crossings are reopening, and arrests for illegal crossings from Mexico fell to about 2,500 on Monday, from more than 10,000 on several days in December, officials said.

“We need to fix the border. There’s virtually unanimous agreement among Democrats and Republicans about that,” Senate Majority Leader Chuck Schumer, D-N.Y., said at the U.S. Capitol on Wednesday. He added: “Everyone’s going to have to give something to get this done.”

Republicans are pressuring Biden and Democrats to accept strict border measures, and they see the high number of migrants arriving at the border as a political weakness for the president.

Senate Republican leader Mitch McConnell told reporters in Kentucky on Tuesday that in a conversation with 81-year-old Biden, he made the case: “You can’t do anything about how old you are, you can’t do anything about inflation, but this is something that’s measurable that you could claim credit for.”

McConnell also said he was approaching the talks with “optimism that somehow we will get this all together and we’re giving it our best shot.”

Sen. James Lankford, the Oklahoma Republican negotiating the Senate agreement, called H.R. 2 “a great bill,” but said it was not realistic to expect the president or Senate Democrats to support the measures.

Senate negotiators have focused on tougher asylum protocols for migrants arriving at the U.S.-Mexico border, bolstering border enforcement with more personnel and high-tech systems, and enforcement measures that would kick in if the number of daily crossings passed a certain threshold.

Sens. Kyrsten Sinema, I-Ariz, Chris Murphy, D-Conn., and Lankford met Wednesday afternoon and said they were trying to agree on legislative text they could present to their colleagues. Sinema said the group was “closing in" on an agreement, but technical work remained before Congress returns to Washington next week.

“We’re going to work out a bill, if we’re successful, that will have Republican and Democratic votes,” said Murphy, the chief Democratic negotiator.

Murphy has raised concern that the longer the talks draw out, the longer it leaves Ukraine's defenses hanging without assured support from the U.S. in the war with Russia.

The Pentagon in late December announced what officials say could be the final package of military aid for Ukraine if Congress does not approve Biden's funding request. The weapons, worth up to $250 million, include air munitions and other missiles, artillery, anti-armor systems, ammunition, demolition and medical equipment and parts.

Russia has unleashed a flurry of missile and drone strikes on Ukraine in the new year.