The U.S. Department of State has revoked the visas of six foreign nationals after they posted comments online criticizing or mocking the assassination of conservative activist Charlie Kirk, deepening the Trump administration's campaign to police speech by foreign visitors in the United States.

"The United States has no obligation to host foreigners who wish death on Americans," the State Department said Tuesday evening on X. "The State Department continues to identify visa holders who celebrated the heinous assassination of Charlie Kirk."

The department's post was followed by screenshots of six social media accounts allegedly belonging to users from Argentina, Brazil, Germany, Mexico, Paraguay, and South Africa. The posts included remarks such as "Charlie Kirk won't be remembered as a hero" and he "devoted his entire life spreading racist, xenophobic, misogynistic rhetoric and deserves to burn in hell." The accounts were not named publicly, but at least two of the individuals were later identified by internet users.

President Donald Trump, who posthumously awarded Kirk the Presidential Medal of Freedom on Tuesday, has repeatedly described the slain Turning Point USA founder as a "martyr for truth." Kirk, 31, was fatally shot at a rally in Arizona last month, an event that sparked a flood of political commentary across U.S. social media.

Trump and Marco Rubio "will defend our borders, our culture, and our citizens by enforcing our immigration laws," the agency wrote in a follow-up post. "Aliens who take advantage of America's hospitality while celebrating the assassination of our citizens will be removed."

Secretary of State Marco Rubio had warned earlier that the administration would revoke the visas of foreigners who "celebrated" Kirk's death. Deputy Secretary of State Christopher Landau said he was "disgusted to see some on social media praising, rationalizing, or making light of the event," and called on Americans to report such posts from visa holders. "Please feel free to bring such comments by foreigners to my attention so that the [State Department] can protect the American people," he wrote in September.

The action follows a series of measures tightening digital scrutiny of foreign nationals. Since June, all international students have been required to make their social media accounts public for visa vetting. A State Department official told Fox News in August that more than 6,000 student visas had been revoked this year, with "200 to 300" cancellations linked to alleged support for terrorism or groups such as Hamas.