Mexico is stopping nearly three times as many migrants as last year, which helps the U.S.

Mexico is stopping nearly three times as many migrants who have crossed its southern border as it was a year ago, a trend that U.S. officials say has helped blunt the surge in crossings of the U.S. border usually seen at this time of year.

Biden administration officials also point to the increased help from Mexico in slowing migration as proof that their relationship with their southern neighbors is more effective than the Trump administration’s.

Former President Donald Trump has derided President Joe Biden’s record and claimed that his administration was more successful at controlling the border.

Early last year, Mexico interdicted roughly 100,000 migrants at its southern border or inside Mexico per month, while the U.S. was apprehending over 193,000 migrants monthly at the U.S.-Mexico border. This year, more migrants are being stopped inside Mexico than in the U.S., with over 280,000 being interdicted in Mexico and 189,000 in the U.S. in March, according to figures obtained by NBC News.

The Mexican government doesn’t publicly share its migrant interdiction numbers like the U.S. does.

The high numbers of migrants stopped in Mexico show how chaotic the U.S. border could become if Mexico cannot sustain its interdiction efforts. Another spike in border crossings could hurt Biden in the coming election.

According to Customs and Border Protection officials, April’s figures, which have yet to be publicly released, are expected to continue to show relatively low numbers compared to the seasonal uptick typically seen in April and May.It isn’t known how many of the migrants Mexico intercepts are actually deported. Many migrants are stopped by Mexican officials at the Guatemala-Mexico border and promptly returned to Guatemala, immigration advocates told NBC News.

Many others are being stopped in northern Mexico and bused to the southern end of the country. From there, they can’t use the CBP One app on their mobile phones to make appointments for U.S. asylum hearings, since the app doesn’t work south of Mexico City, said Amy Fischer, director of refugee and migrant rights at Amnesty International USA.

“In one way, they are doing the dirty work of the U.S. in order to keep people from accessing the U.S. southern border and exercising their right to seek safety,” Fischer said.

Certain groups, like unaccompanied children and migrants traveling as families, receive special protection under Mexican law that limits their deportation.

U.S. officials say Mexico’s willingness to interdict more migrants, a costly process, is in large part due to increased dialogue between the two countries on issues like immigration, fentanyl and illegal firearms trafficking.

Both Biden and Mexican President Andrés Manuel López Obrador, known as AMLO, recognized the severity of the problem at the end of last year when Mexico’s funding to stop migrants ran low and the number of migrants crossing the U.S.-Mexico border surged to record highs.

At the end of December, Biden held a call with López Obrador and sent Homeland Security Secretary Alejandro Mayorkas and Secretary of State Antony Blinken to Mexico to meet with their counterparts. Since then, Mexico has interdicted at least 270,000 migrants each month.

“President Biden and President AMLO have developed a relationship in which they talk about the shared challenges [of migration], and they both jointly recognize the shared challenges,” a senior Biden administration official said. “They’ve had multiple conversations and multiple calls over the last couple of years tackling and talking about this issue.”

The Trump administration threatened Mexico with increased tariffs and disruptions in trade if it didn’t comply with policies like Remain in Mexico, which forced immigrants seeking asylum in the U.S. to wait in poor conditions in northern Mexico.

“We have treated Mexico with respect as a sovereign equal,” the senior Biden administration official said. “That’s a difference with this administration’s approach.”

A history of cooperation

The Biden administration isn’t the first to work jointly with Mexico to address migration and other border issues.

In 2008, during George W. Bush’s administration, the Merida Initiative — a security agreement between the U.S. and Mexico — was launched to reduce violence and fight drug trafficking. Congress approved $1.5 billion for the initiative over two years, enabling the purchase of equipment like helicopters and other aircraft to support the efforts of Mexican law enforcement.

During the Obama administration, the U.S. and Mexico expanded cooperation to include combating transnational criminal organizations by providing forensic equipment and training to Mexican law enforcement and improving immigration enforcement in Mexico.

The Trump administration focused on reducing synthetic drug production and refining border interdiction and port security. In 2018, it reportedly wanted to pay Mexico $20 million to help deport thousands of migrants who entered Mexico in hope of reaching the U.S. The sum, according to CNN and The New York Times, would be used to fund bus and airplane tickets to send migrants back to their home countries. In 2019, Trump stopped threatening tariffs against Mexico after it agreed to crack down on crossings of its southern border. Mexico deployed 6,000 troops to its border with Guatemala to intercept migrants.

During the Biden administration, the U.S. and Mexico announced a new security cooperation agreement in 2021 called the Bicentennial Framework. The Bicentennial Framework replaced the Merida Initiative and emphasized preventing transborder crime by minimizing human and arms trafficking and disrupting illicit drug supply chains.

This article was originally published on NBCNews.com