WASHINGTON (AP) — In an evening announcement, President-elect Donald Trump railed against Mexico and Canada, accusing them of allowing thousands of people to enter the U.S.

Hitting a familiar theme from the campaign trail and his first term in office, Trump portrayed the country's borders as insecure and immigrants as contributing to crime and the fentanyl crisis. In an announcement that could have stark repercussions, he threatened to impose 25% tariffs on everything coming into the country from those two countries.

Trump's anti-immigration rhetoric has resonated with voters concerned about immigration and crime. Yet there's more to the story than Trump's short statement suggested.

A look at what the numbers and studies say about border crossings, fentanyl smuggling and whether there's a connection between immigration and crime:

Border crossings

The number of migrants crossing the U.S.-Mexico border is a key metric watched intensely by both Republicans and Democrats.

Customs and Border Protection, an arm of the Department of Homeland Security, releases monthly statistics that track everything from drug seizures to cross-border trade. One of the metrics tracked is the number of Border Patrol arrests or encounters each month with people entering the country between the official border crossings — known as the ports of entry.

The vast majority of those arrests happen at the southern border.

Those numbers have actually been falling this year under the Biden administration. The Border Patrol made 56,530 arrests in October, which is about a four-year low.

It hasn't always been like that. The Biden administration struggled to bring down the growing number of migrants coming to the southern border. A little less than a year ago, in December 2023, the Border Patrol made about a quarter of a million arrests along the southern border — an all-time high. Cross-border trade was damaged as border agents were reassigned to help process migrants and train traffic was temporarily shut down.

Since then, the numbers of people encountered at the southern border have dropped and stayed down through a combination of stricter enforcement on the Mexican side and asylum restrictions announced earlier this year by the Biden administration.

Republicans put a caveat on those numbers.

They have frequently accused the Biden administration of using an app called CBP One to let hundreds of thousands of people into the country who otherwise wouldn't be allowed in. They've described the program where 1,450 people a day can schedule an appointment to come into the U.S., as essentially a way to keep the border encounter numbers artificially low.

On the northern border, the numbers are much smaller. Border Patrol made 23,721 arrests between October 2023 and September 2024, compared with 10,021 the previous 12 months.

Trump also struggled to get a handle on illegal border crossings. Arrests topped 850,000 in 2019, nearly triple the amount two years earlier, though still far below the tally of more than 2 million for two different years under Biden.

Drug smuggling

Trump and many Republicans have often portrayed the U.S.'s southern border as wide open to drug smuggling. They have also linked immigrants to drug smuggling and accused Mexico of doing little to stop it.

Much of America's fentanyl is smuggled from Mexico.

The fentanyl scourge began well before Biden took office. Border seizures have jumped sharply under Biden, which may partly reflect improved detection. About 27,000 pounds (12,247 kilograms) of fentanyl was seized by U.S. authorities in the 2023 government budget year, compared with 2,545 pounds (1,154 kilograms) in 2019, when Trump was president.

Cooperation between the Mexican and U.S. governments on fighting drug smuggling undoubtedly suffered under President Andrés Manuel López Obrador, who left office at the end of September.

Before López Obrador took office in December 2018, the U.S. worked closely with Mexico's military to take down drug capos.

But López Obrador, a nationalist and folksy populist, railed against the violence set off by the drug war waged by his predecessors and the Americans. He proposed addressing the root societal causes of violence found in poverty and a lack of opportunity for young people, in what he called "hugs, not bullets."

For years, López Obrador denied that Mexico made fentanyl, despite evidence to the contrary, including statements from his own security officials. He blamed U.S. society, where he said families push children out of home too early, for cultivating addicts.

It's only two months into the term of President Claudia Sheinbaum.

But while most of the fentanyl comes from Mexico, statistics show that it is Americans who are doing the smuggling across the border. According to the U.S. Sentencing Commission, 86.4% of people sentenced for fentanyl trafficking crimes in a 12-month period ending September 2023 were American citizens.

Crime and immigration

Trump also has argued that the influx of immigrants is causing a crime surge in the U.S., although statistics show violent crime is on the way down.

Texas is the only state that tracks crime by immigration status. A study published by the National Academy of Sciences, based on Texas Department of Public Safety data from 2012 to 2016, found people in the U.S. illegally had "substantially lower crime rates than native-born citizens and legal immigrants across a range of felony offenses."

While FBI statistics do not separate out crimes by the immigration status of the assailant, there is no evidence of a spike in crime perpetrated by migrants, either along the U.S.-Mexico border or in cities seeing the greatest influx of migrants, like New York. Studies have found that people living in the U.S. illegally are less likely than native-born Americans to have been arrested for violent, drug and property crimes.

Some crime is inevitable given the large population of immigrants. There were an estimated 11 million people in the country illegally in January 2022, according to the latest estimate by U.S. Homeland Security Department. In 2022, the Census Bureau estimated the foreign-born population at 46.2 million, or nearly 14% of the total, with most states seeing double-digit percentage increases in the last dozen years.

Republicans have highlighted high-profile crimes by immigrants such as the February killing of 22-year-old Laken Riley in Georgia and argued that any crime committed by someone in the country illegally is a crime that shouldn't have happened.

A Venezuelan man who entered the country illegally was convicted and sentenced to life in prison this month in Riley's killing.