Following a speech in which he declared a national emergency at the southern border Friday, President Donald Trump said he uses “many stats” to back his claims of escalating violence, illegal immigration rates, and drug entry from Mexico to the United States.

Sparring with reporter Brian Karem, who asked the president to clarify his source for the statistics, which contradict reports from the federal Drug Enforcement Administration, Trump said he relies on “many stats,” including those from Homeland Security, regarding immigration and drugs at the border. Trump did not specify his other sources.

The testy exchange was the latest dispute over the Trump administration’s claims of a growing immigration threat at the southern border, and the figures purported to back up such statements.

“I get my numbers from a lot of sources, like Homeland Security, primarily, and the numbers I have from Homeland Security are a disaster,” Trump said, after raising his voice and telling Karem, a White House reporter for Playboy and political analyst for CNN, to “sit down."

“And you know what else is a disaster? The numbers that come out of Homeland Security, Kirstjen [Nielsen], for the cost that we spend, and the money that we lose because of illegal immigration. Billions and billions of dollars a month, billions and billions of dollars and it’s unnecessary,” Trump continued.

“So your own government’s stats are wrong, are you saying?” Karem asked.

“No, no, I use many stats,” Trump responded. “Let me tell you, you have stats that are far worse than the ones that I use. But I use many stats, but I also use Homeland Security.”

The president has repeatedly claimed that there is a “crisis” at the U.S.-Mexico border in posturing for a wall. Though there is no standard specified by Congress for justifying a national emergency, researchers have questioned the numbers and context behind Trump’s statements.

While it is true that the number of people caught while trying to cross into the United States from Mexico has recently risen, the total is still significantly below its peak in 2007, when President George W. Bush doubled the number of Border Patrol agents, according to FactCheck.org.

There were about 12 million undocumented immigrants in the United States as of 2015, according to a Department of Homeland Security study from December. The statistics also suggested “a declining rate of growth of new illegal immigration and/or an increasing share of new illegal aliens being repatriated or otherwise returning home,” according to the report.

A Pew study estimated there were around 10.7 million unauthorized immigrants in the United States in 2016, a 13.7 percent decline from 2007.

And while research is scant on the cost of unauthorized immigrants to America, the highest costs would generally regard health care and education. Many undocumented immigrants, however, pay taxes and are not eligible to receive the most expensive healthcare benefits, such as Medicaid, the New York Times reported.

A 2016 study from the National Academy of Sciences found that immigrants — those who entered the country both legally and illegally — positively benefited the economy.

During his remarks Friday, Trump also doubled down on his claims of a flow of illicit drugs at the southern border.

“A big majority of the big drugs, the big drug loads don’t go through ports of entry,” the president said. “They can’t go through ports of entry. You can’t take big loads because you have people. We have some very capable people, the Border Patrol, law enforcement, looking.”

However, his own government’s findings disagree. According to the Drug Enforcement Agency, traffickers smuggle most drugs to the U.S. and Philadelphia through legal crossing points that are patrolled, not at unguarded stretches of the border.