A vet from Glasgow says she is "upset" and "afraid" after being prevented from flying to the US under President Donald Trump's executive order barring people from several Muslim countries.
Hamaseh Tayari, who holds an Iranian passport, had been due to fly home from a holiday in Costa Rica via New York.
But she has been told she cannot fly to the USA because of the order.
The American president said the measures would "keep radical Islamic terrorists out of the US".
The 90-day travel ban affects nationals from Syria, Iran, Iraq, Libya, Somalia, Sudan and Yemen.
Speaking to BBC Scotland from San Jose airport in Costa Rica, Dr Tayari, who works at the University of Glasgow, said: "We arrived at the airport this morning at five o'clock for the check-in to fly to New York, and then from New York to Glasgow.
"The people at the check-in told me that I was not allowed to take the plane because of the new rules.
"The company was really helpful. I'm still in their offices trying to find new flights.
"They've given us food and coffee, and they're really supporting us. It's not their fault, but it's a crazy thing that I really didn't expect to happen to me."
Dr Tayari grew up and studied in Italy, qualifying as a vet in 2012.
She was awarded a PhD by the University of Pisa after a short period of extra training in Switzerland and moved to Glasgow to continue her studies in November 2015.
She said: "I still have Iranian nationality, because I've never thought about changing it.
"I've never had any problems until now, maybe I've had to wait a bit longer for visas, but nothing like this has happened to me.
"In my passport I have a regular transit visa for the USA, but they told me the visa is not any more valid."
She was left trying to find alternative routes home.
However, Dr Tayari said that, owing to her passport, "flying through Cuba, Panama, Mexico, all of these other places, I need a visa.
"The only thing that I've found is a direct flight from San Jose [in Costa Rica] to Madrid."
Booking that flight and connection onwards to London and Glasgow has cost her and her boyfriend almost £2,600 which she described as "all our money for the next few months".
She said: "I don't know how we'll afford to pay the rent, the bills, and the food," adding that the situation had left her "completely shocked".
"I thought maybe I didn't understand what's going on. I tried to ask again, if I understood properly.
"Afterwards, I was really upset. I'm still upset. I'm more than angry. I'm really upset. And, I'm a little bit afraid."
A spokesman for the University of Glasgow said: "We were extremely concerned at the difficulties which one of our postgraduate students encountered on trying to return to the UK via the United States after holidaying in Costa Rica.
"We have been in touch with Hamaseh who has made arrangements to get back to Glasgow via an alternative route. The university will do all that we can to support her."