Immigration authorities announced on Wednesday that social media activity perceived as anti-Semitic, as well as the "physical harassment of Jewish" people, will now be grounds for denying applicants US visas and permanent residency.
US Citizenship and Immigration Services said the new guidance will take effect immediately and affect those applying for green cards, student visas and teaching positions at universities.
“There is no room in the United States for the rest of the world’s terrorist sympathisers and we are under no obligation to admit them or let them stay here,” said Tricia McLaughlin, Department of Homeland Security assistant secretary for public affairs."
She said Kristi Noem, US Secretary of Homeland Security, "has made it clear that anyone who thinks they can come to America and hide behind the First Amendment to advocate for anti-Semitic violence and terrorism – think again. You are not welcome here.”

Under the new rule, authorities will consider social media content that indicates support for Hamas, Palestinian Islamic Jihad, Hezbollah and the Houthis as grounds for the rejection of visas and said the move would protect the US from extremists and "terrorist aliens".
The move follows President Donald Trump's executive order, signed in January, that called for the revocation of visas of foreign students and others who took part in pro-Palestinian protests on university campuses as part of what the administration has called an effort to combat anti-Semitism.
The Trump administration has said anti-Semitism on campuses and elsewhere has risen sharply since the Hamas-led attack on Israel on October 7, 2023 that killed 1,200 people and triggered the war on Gaza, now 18 months old.
However, free speech advocates and pro-Palestinian groups fear the measures are being used to silence critics of a war that has killed more than 50,800 Palestinians in Gaza and reduced much of the coastal enclave to rubble.
Whether the measure will be applied to people currently in the US legally and already vetted has yet to be established.
The practice of immigration officials monitoring social media activity is not new. It is known date back to the second term of former president Barack Obama (2013-2017) – though was perhaps in operation earlier – and intensified during Mr Trump's first term in office (2017-2021).
The development comes amid the high-profile case of Mahmoud Khalil, a green card-holding Palestinian activist and Columbia University graduate who was detained by plainclothes immigration officials last month. Authorities say he supported Hamas, without providing evidence, and moved to revoke his green card and have him deported.
An immigration judge on Tuesday said the government has until 5pm on Wednesday to present evidence as to why Mr Khalil, who served as a negotiator with the Columbia administration during the student protests at the university in New York City last year, should be deported.
The judge said that without compelling evidence, she may order his release on Friday.