The United Kingdom (UK) on Thursday issued a rare updated travel advisory to residents hoping to visit the United States, warning them that there would be harsh consequences for British citizens in the U.S. who violate the country's immigration laws.

The warning comes as President Donald Trump cracks down on illegal immigration, including deporting migrants that are in the country illegally. The administration is largely focusing on migrants who commit other crimes outside of being in the U.S. illegally, but warned all illegal immigrants that they could be deported.

The new advisory instructs all British travelers to comply with all "entry, visa and other conditions of entry," instead of just informing residents that U.S. authorities “set and enforce entry rules," Reuters reported.

"You should comply with all entry, visa and other conditions of entry," the advisory said. "The authorities in the US set and enforce entry rules strictly. You may be liable to arrest or detention if you break the rules."

The new advisory comes after British authorities said earlier this month that they were helping a British national who was detained in the U.S. Germany has also updated its travel advice after three citizens were detained trying to enter the U.S., per The Hill.

The French government also revealed on Thursday that one of its citizens was allegedly refused entry on U.S. soil over his criticism of Trump's policies, according to Politico. Just The News has not independently verified the claim.

Misty Severi is a news reporter for Just The News. You can follow her on X for more coverage.