Biden and Mexico’s President Vow Combined Action on Illegal Immigration

President Biden and the president of Mexico on Monday vowed combined action to prevent illegal immigration as Mr. Biden remains under intense political pressure from all sides to address the impact of surging border crossings ahead of the presidential election this year.

In a joint statement, Mr. Biden and President Andrés Manuel López Obrador said they had ordered their national security aides to “work together to immediately implement concrete measures to significantly reduce irregular border crossings while protecting human rights.”

The statement, which followed a phone call between the two leaders on Sunday, did not specify any actions under consideration. A senior administration official declined to elaborate on what the United States and Mexico might “immediately implement” and said only that the two sides would continue to have conversations about the issue.

The lack of clarity leaves in limbo an issue that could be a deciding factor in whether Mr. Biden stays in the Oval Office for another four years. Polls of both Republicans and Democrats in recent months indicate that the situation at the border is a serious concern. And even some of the president’s most fervent supporters in liberal cities are demanding that he do something to stanch the flow of migrants.

The president’s latest plan to do that — with a highly restrictive immigration bill that had some bipartisan support — fell apart over the last several months as Republicans in the House blocked it. Mr. Biden had called for the legislation to be passed alongside financial aid for Israel, Ukraine and Taiwan, but when Congress finally reached a deal on the funding earlier this month, the border legislation was not included.