A French scientist has been denied entry to the United States for having phone messages critical of Trump.

BarcelonaU.S. authorities have denied entry to a French scientist after immigration officers at the airport found messages critical of the Trump administration on his phone. The researcher at France's National Center for Scientific Research (CNRS) was randomly checked upon arrival in March, and his computer and phone were searched.

"I learned with concern that a French researcher traveling to a conference near Houston was denied entry to the United States and expelled," French Education and Research Minister Philippe Baptiste said in a statement to Agence France-Pres ( The WorldThe expelled researcher was traveling for work for France's National Center for Scientific Research (CNRS).

"Apparently, this measure was taken by the US authorities because the researcher's phone contained exchanges with colleagues and friends in which he expressed a personal opinion on the Trump administration's search policy," the minister added. It is unclear which conference the researcher was supposed to attend, but the 56th Lunar and Planetary Science Conference (LPSC) was scheduled to take place in Houston between March 10 and 14. The incident, according to the French agency, occurred on March 9, but has now been made public.

The FBI opened an investigation but later dropped the charges.

US authorities accused him of having "hateful messages toward Trump that can be classified as terrorism." Another source told AFP that the FBI had opened an investigation, but that "the charges were dropped" before he was sent back to Europe.

"Freedom of opinion, research, and academic freedom are values that we will continue to proudly defend. I will defend the right of all French researchers to be faithful to these values, while always respecting the law," Baptiste said.

In recent months, Baptiste has been highly critical of Trump and Elon Musk for making significant cuts to scientific research budgets. On the same day the researcher was banned from entering the United States, Baptiste published a letter inviting American researchers to move to France. In the same vein, he criticized the way research in health, climate, energy, and artificial intelligence "is being destroyed with a chainsaw in the United States."