Students around the world are anxious and in limbo, they say, as the Trump administration makes plans to temporarily halt US student visa appointments.

An official memo seen by BBC's US partner CBS ordered a temporary pause in appointments as the state department prepares to increase social media vetting of applicants for student and foreign exchange visas.

It is part of a wide-ranging crackdown by US President Donald Trump on some of America's most elite universities, which he sees as overly liberal.

For students, the changes have brought widespread uncertainty, with visa appointments at US embassies now unavailable and delays that could leave scholarships up in the air.

Some students told the BBC that the confusion has even left them wishing they had applied to schools outside the US.

"I already regret it," said a 22-year-old master's student from Shanghai, who did not wish to be named for fear of jeopardising their visa to study at the University of Pennsylvania.

The student said they feel lucky their application was approved, but that has not eased their uncertainty.

"Even if I study in the US, I may be chased back to China without getting my degree," they said. "That's so scary."

Asked about the decision to pause all student visa appointments, state department spokesperson Tammy Bruce told reporters on Tuesday: "We take very seriously the process of vetting who it is that comes into the country, and we're going to continue to do that."

As part of his wider crackdown on higher education, Trump has moved to ban Harvard from enrolling international students, accusing the school of not doing enough to combat antisemitism on campus.

Harvard filed a lawsuit in response, and a judge has halted Trump's ban for now, with a hearing on the matter scheduled for 29 May.

A student from Guangzhou City, who runs a consultancy group for Chinese students wishing to study in the US, said they are not sure how to advise applicants because the rules keep changing.

The student, who also wished not to be named, added that they think there will be fewer students who see the US as a viable education option.

More than 1.1 million international students from over 210 countries were enrolled in US colleges in the 2023-24 school year, according to Open Doors, an organisation that collects data on foreign students.

Universities often charge these international students higher tuition fees, a crucial part of their operating budgets.

For Ainul Hussein, 24, from India, the visa implications are both financial and personal.

Mr Hussein said he was excited to begin the next chapter of his life in New Jersey, enrolled in a master's of science programme in management.

He received a I-20 document from the university - a crucial piece of paper that allows him to apply for a US student visa.

But recent processing delays left him "deeply worried", he said, with appointments at consulates now either postponed or unavailable.

Foreign students who want to study in the US usually must schedule interviews at a US embassy in their home country before approval.

He said he may be forced to book flights to the US, still unsure of the situation. He also risks losing his scholarship if he has to defer his studies.

Students in the UK are being affected, too.

Oliver Cropley, a 27-year-old from Norwich, said he was due to study abroad for a year in Kansas, but that plan is now in jeopardy.

"Currently I've no student visa, despite forking out £300 on the application process," Mr Cropley said.

News of the US pausing visa applications is "a huge disappointment".

He, too, risks losing a scholarship if he is unable to complete his study abroad in the US, and may have to find last-minute accommodation and liaise with the university to make sure it does not delay him academically.

Alfred Williamson, from Wales, told Reuters he was excited to travel after his first year at Harvard, but couldn't wait to get back. But now, he hasn't heard about his visa.

It's "dehumanising", he told Reuters.

"We're being used like pawns in the game that we have no control of, and we're being caught in this crossfire between the White House and Harvard," Mr Williamson told the news agency.