Brazil is making it easier for the United States to deport undocumented Brazilians by asking U.S. airlines to board deportees even when they have no valid passports, following pressure from the Trump administration, three Brazilian government sources said.

The Federal Police sent airlines a memo in June allowing them to board Brazilian deportees with just a certificate of nationality issued by a consulate if they lack a valid passport, previously needed to travel to Brazil, the sources said.

The move by right-wing President Jair Bolsonaro’s government aims to facilitate repatriation of deportees by U.S. Immigration and Customs Enforcement (ICE) and efforts by the Trump administration to speed the removal of undocumented immigrants.

The officials, who requested anonymity because they were not authorized to speak publicly on the matter, said Brazil has come under increasing pressure from the Trump administration to facilitate deportations of its detained nationals, to the point of risking sanctions.

They did not detail what kind of sanctions.

“When Donald Trump became U.S. president, illegal immigration became a central political issue. Pressure increased a lot and Brazil was even threatened with sanctions,” one of the sources with knowledge of the matter told Reuters.

Brazil was labeled as “at risk of non-compliance” with the repatriation of deportees in a U.S. Department of Homeland Security report in March on the barriers ICE faces to timely removal of detained immigrants.

Trump has been cracking down on recalcitrant countries that do not accept immigrants ordered deported, under an executive order issued immediately after he took office.

According to Reuters, the deportation of undocumented Brazilians has risen from 1,413 in fiscal year 2017 to 1,691 in fiscal 2018, with Brazilians the sixth-largest group of nationals being removed from the United States, according to ICE data.

This fiscal year there have been 1,117 removals of Brazilians through June 10, ICE said. The U.S. fiscal year runs from Oct. 1 through Sept. 30.

Brazil’s Foreign Ministry confirmed that certificates of nationality are issued by its consulates in the United States when detained deportees have exhausted their appeals process and have no passport. Brazilian passports are issued only to nationals who apply for them.

Many countries have arrangements with the U.S. government and foreign countries that allow for a document – other than a passport – issued by an embassy or consulate to serve as an authorization to travel.

Delta Airlines and American Airlines did not respond to requests for comment.

As of December, there were 334 Brazilians in ICE detention awaiting trial or deportation, the ministry said.

Since he took office in January, Bolsonaro has established close ties with Trump and the two are looking to negotiate a trade agreement.

Bolsonaro has made disparaging statements about immigrants. In March, speaking on Fox News during a visit to Washington, he praised Trump’s plan for a wall on the Mexican border, adding that “most immigrants do not have good intentions.”

His son Eduardo Bolsonaro, whom he has nominated to be Brazil’s ambassador in Washington, told reporters during that visit that illegal Brazilian immigrants were “a problem for Brazil, an embarrassment to us.”