Vice President JD Vance stoked some controversy last week with his speech at the Munich Security Conference, where he criticized European allies on immigration, free speech and other issues.

At CPAC on Thursday, he stood by the themes in his address after receiving a standing ovation from the audience.

“We cannot rebuild the United States of America or Europe by letting millions and millions of unvetted migrants come into our country and it has to stop," Vance said. He added: "You can't just stop it. You have to allow European peoples, and American people too, to raise issues about it. You have to allow free speech to debate this stop."

Asked about the future of U.S. alliances on the continent, Vance said they would continue to have "important" partnerships with Europe.

"But I really do think the strength of those alliances is going to depend on whether we take our societies in the right direction ... That friendship is based on shared values," he said.

Polygraphs that the Department of Homeland Security administers will include a question about whether the employee had unauthorized communications with the media or a nonprofit organization.

DHS Secretary Kristi Noem said leaks have stymied immigration enforcement operations and warned that polygraphs may help crack down on leakers, according to a memo described to ABC News.

Noem appeared on Fox News' "Hannity" and confirmed the use of polygraphs to weed out the "leakers," who may have leaked Immigration and Customs Enforcement operations.

"Yes, I do have suspicions," she said. "I need to be sure and I need to be certain, so we have different tools we can use and one of those is ensuring we're using polygraphs to look at all of our employees, all of these people involved in these operations, to make sure they're telling the truth on what they have done in the past that may have jeopardized our operations."

She said DHS is a "national security agency" and a "law enforcement agency" and this is one of the authorities she can use to find out who is doing the "nefarious" activity.

Bloomberg Government was first to report on the memo.

Some DHS components already use polygraph tests when an agent first onboards, for example, U.S. Customs and Border Protection.

-ABC News' Luke Barr

President Donald Trump signed an executive order on Wednesday night directing federal agencies to "identify all federally funded programs currently providing financial benefits to illegal aliens and take corrective action," according to a fact sheet released by the White House.

It intends to ensure that federal funding will not be used to "support 'sanctuary' policies or assist illegal immigration" and mandates improvements in eligibility verification.

The order also calls for identifying all other sources of federal funding for those unlawfully present in the United States, and it seeks recommendations for additional agency actions to align federal spending with the order within 30 days.

Agencies are tasked with referring "improper receipt or use of Federal benefits to the Department of Justice and the Department of Homeland Security for appropriate action."

The White House noted in its fact sheet that illegal migrants are already barred from welfare programs, raising the question of how much funding Trump might be expecting to withhold. It also fails to define "illegal alien" -- the term it applies -- for the purposes of executing this order.

- ABC News' Molly Nagle

President Donald Trump's administration on Wednesday lost its appeal to lift a nationwide injunction against his executive order on birthright citizenship.

The Ninth Circuit Court of Appeals said a closer review of the case will move forward in its court, with arguments slated for June.

In a concurring decision, Judge Danielle Jo Forrest -- who Trump nominated to the Ninth Circuit in 2019 -- defended the court's decision to deny the request for an emergency stay, arguing that rushing the decision birthright citizenship risks "eroding public confidence" at a critical moment in the country's history.

"When we decide issues of significant public importance and political controversy hours after we finish reading the final brief, we should not be surprised if the public questions whether we are politicians in disguise," Forrest wrote, before defending her decision to deny Trump's emergency appeal.

Trump's executive order on birthright citizenship was blocked by four separate federal judges across the country, each of whom determined that the policy directly violated the Constitution.

-ABC News' Peter Charalambous