WASHINGTON (AP) — A delegation of top U.S. officials is expected to visit Mexico soon as negotiations over how to enforce immigration rules at the two countries' shared border continue on Capitol Hill.

Republican and Democratic lawmakers are debating border policy changes as part of a larger conversation over U.S. assistance for Ukraine and Israel, which are top foreign policy priorities for the White House.

The upcoming visit to Mexico comes amid controversy over the closure of two rail crossings in Texas earlier this week. U.S. officials said the personnel needed to be redeployed to handle high numbers of migrants illegally crossing the border. Mexican businesses warn that the closings are hampering trade.

President Joe Biden spoke with Mexican President Andrés Manuel López Obrador on Thursday and agreed that additional border enforcement was needed so the crossings can be reopened, according to White House national security spokesman John Kirby.

Kirby said Biden asked Secretary of State Antony Blinken, Homeland Security Secretary Alejandro Mayorkas and White House homeland security adviser Liz Sherwood-Randall to travel to Mexico in the coming days to meet with López Obrador and his team to discuss further actions that can be taken to address the challenge.

A U.S. official said the trip would likely happen the Wednesday after Christmas. It was originally tentatively scheduled for this Saturday. The official spoke on the condition of anonymity to discuss planning.

"Their visit will really be about getting at the migratory flows and talking to President López Obrador and his team about what more we can do together," Kirby said at a White House briefing.

Mexican companies are so eager for the border crossings to reopen that the leader of the Industrial Chamber of Commerce wrote on his social media accounts late Wednesday that a deal had been brokered to get them reopened. A U.S. Embassy spokesman quickly denied that, saying they remained closed.

The Mexican Employers' Association described the closure of rail crossings into Eagle Pass and El Paso, Texas, as a "failure of migration policy." The organization said the situation was causing losses of $100 million per day in delayed shipments.

Mexico receives much of the corn and soy products it needs to feed livestock by rail from the United States. Auto parts and automobiles also frequently are shipped by rail in Mexico.

"We energetically but respectfully call on the governments of Mexico and the United States to address the migration crisis which is affecting the flow of goods, given that this measure only damages the economies of both nations," the association wrote in a statement.

U.S. Customs and Border Protection said Sunday the decision was made "in order to redirect personnel to assist the U.S. Border Patrol with taking migrants into custody."

But is also appeared the U.S. government wants Mexico to crack down on migrants riding railcars to the U.S. border.

In the Sunday statement, the CBP wrote that "after observing a recent resurgence of smuggling organizations moving migrants through Mexico via freight trains, CBP is taking additional actions to surge personnel and address this concerning development, including in partnership with Mexican authorities."

Migrants often ride freight trains through Mexico, hopping off just before entering the U.S.

Elsewhere, the Lukeville, Arizona, border crossing is closed, as is a pedestrian entry in San Diego, so that more officials can be assigned to the migrant influx. Illegal crossings at the U.S. southwestern border topped 10,000 some days in December, an abnormally high level.

___

Stevenson reported from Mexico City. Associated Press writers Matthew Lee and Aamer Madhani contributed to this report.