The Biden administration this week will reopen four ports of entry at the southern border that were previously closed due to a record influx of migrants, senior administration officials said Tuesday.

The four ports of entry that will be operational again on Thursday are located in Eagle Pass, Texas; San Ysidro, California; Lukeville, Arizona; and Nogales, Arizona.

Those border crossings were closed for much of December as U.S. Customs and Border Protection shifted resources to respond to the influx of migrants traveling to the U.S. The planned reopenings come after a record-setting month where Customs and Border Protection agents encountered more than 300,000 migrants at the southern border.

On Monday, CBP encountered fewer than 500 migrants in the Del Rio sector of Texas, which includes Eagle Pass. A senior administration official called that number a “significant improvement over where we have been in recent weeks.”

“While it is important to note as well that this is the time of year when we normally expect to see encounters decrease over the holiday period, it’s also important to note that the closing of ports of entry is something we do as a last resort,” the senior administration official said. “It’s something that we do not take lightly.”

The drop was attributed in part to increased enforcement from Mexico, though no specifics were provided.

“We are encouraged that we have seen some increased enforcement in Mexico and a decrease in our encounters in recent days,” the official said.

The Biden administration has spoken with Mexican train companies and the Mexican government after seeing upwards of a thousand migrants riding on top of commercial trains in Mexico.

“We anticipate the encounter numbers at the border will continue to fluctuate,” a senior administration official said.

Administration officials also acknowledged reports of a migrant caravan that appears to be heading to the U.S. border, with one noting that recent reports indicated that the caravan has “not moved in several days” from a city in southern Mexico.

“We’re encouraged to see that it isn’t moving and seems to be reducing significantly in size,” the official said.

Administration officials did not provide any update on the Senate border funding talks on Capitol Hill, saying only that negotiations continued over the holiday break and that they were “encouraged by the progress being made.”

Three lead Senate negotiators met Tuesday to renew in-person border discussions for the first time since leaving for the holidays. Sens. Chris Murphy, D-Conn.; Kyrsten Sinema, I-Ariz.; and James Lankford, R-Okla., met with Department of Homeland Security Secretary Alejandro Mayorkas for nearly two hours.

President Joe Biden’s proposed $106 billion funding package would provide aid for Ukraine and Israel, as well as funding for U.S. border operations; however, it is stuck in Congress as Republicans say they won’t approve the funding without implementing tougher immigration and border policies.