U.S. Immigration and Customs Enforcement deported more than 270,000 people to 192 countries over a recent 12-month period, the highest annual tally in a decade, according to a report released Thursday that illustrates some of the financial and operational challenges that President-elect Donald Trump will face to carry out his pledge of mass deportations.

ICE, the main government agency responsible for removing people in the country illegally, had 271,484 deportations in its fiscal year ended Sept. 30, nearly double from 142,580 in the same period a year earlier.

It was ICE's highest deportation count since 2014, when it removed 315,943 people. The highest it reached during Trump's first term in the White House was 267,258 in 2019.

Increased deportation flights, including on weekends, and streamlined travel procedures for people sent to Guatemala, Honduras and El Salvador fueled the increase, ICE said. The agency had its first large flight to China in six years and also had planes stop in Albania, Angola, Egypt, Georgia, Ghana, Guinea, India, Mauritania, Romania, Senegal, Tajikistan and Uzbekistan.

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Also Thursday, U.S. Customs and Border Protection said authorities made 46,612 arrests for crossing the border illegally from Mexico in November, down 18% from 56,526 a month earlier and more than 80% from an all-time high of 250,000 in December 2023. Arrests fell by half when Mexican authorities increased enforcement within their own borders a year ago and by half again when President Joe Biden introduced severe asylum restrictions in June. The November numbers were the lowest since July 2020 and indicate that a widely anticipated spike after Trump was elected president didn't happen immediately.

Over the 12-month period ended Sept. 30, Mexico was the most common destination for deportees (87,298), followed by Guatemala (66,435) and Honduras (45,923), the ICE report said. Mexico and Central American countries are expected to continue to bear the brunt of deportations, partly because those governments more readily accept their respective citizens than some others and logistics are easier.

Still, ICE's detention space and staff limited its reach as the number of people it monitors through immigration courts continued to mushroom. The agency's enforcement and removals unit has remained steady at around 6,000 officers over the last decade while its caseload has roughly quadrupled to 7.6 million, up from 6.1 million in the last year alone.

ICE detained an average of 37,700 people a day over the recent 12-month period, a number determined by congressional funding. With detention space a potential hurdle for mass deportations, the state of Texas is offering rural land as a staging area.

ICE made 113,431 arrests during the latest period, down 34% from 170,590 a year earlier. The agency said a need to focus resources on the border with Mexico diverted attention from making arrests in the country's interior.