U.S. Secretary of State Marco Rubio has directed U.S. embassies around the world to scrutinise social media posts of visa applicants for content critical of the United States and Israel before approving their applications.

This move followed the executive order signed by President Donald Trump after he returned to the White House, granting the Department of State the go-ahead to revoke visas of international students and other temporary visa holders suspected to have engaged in anti-American activities.

In the instructions cable sent to U.S. diplomatic missions around the world on March 25, Mr Rubio directed that starting immediately, consular officers must refer certain student and exchange visitor visa applicants to the “fraud prevention unit” for a “mandatory social media check,” the New York Times reported, citing two government officials.

The fraud prevention unit of an embassy or consulate’s section for consular affairs, which issues the visas, helps screen applicants.

The Times reported that the cable also described broad parameters visa officers must use in determining whether to grant or deny visa applications, including scrutinising posts of student and exchange applicants who were granted visas between October 7, 2023, and August 31, 2024, for potential cancellations.

Mr Rubio stated in the cable that applicants can be denied a visa if their behaviour or actions show they bear “a hostile attitude toward U.S. citizens or U.S. culture (including government, institutions, or founding principles).”

Since January, Mr Rubio has revoked more than 300 visas, many of them belonging to students, for participating in activities deemed critical of Israel over the ongoing war in Gaza, with critics accusing the Trump administration of having no regard for the Constitution.