Tehran - Last April, Saeed Qurbani, 34, a computer engineer, left for the United States after winning a green card lottery. Qurbani and his wife had applied five times before they finally won it in 2014, and moved a year later to southern California upon a friend's advice.

Saeed's mother, Nayereh, 54, says her son was planning to return home, for the first time in a year, for a family reunion during Norouz [the Persian New Year] in March. However, following US President Donald Trump's executive order on visa bans for the citizens of several countries, including Iranian nationals, Nayereh fears she might not see her son for some time.

"I am so sad and simply don't understand why he [Trump] has banned Iranians!" she told Al Jazeera.

"My son was going to come home for New Year celebrations. I have been counting the days to reunite with him. It is really hard to imagine that Saeed is locked up there and can't get in and out."

Nayereh is one of the thousands of Iranians who are still reeling from Trump's executive order on visa bans for Iranian nationals. "It is unfair and ridiculous to put such a ban on Iranians. Iranians have never been violent or terrorists! This [decision] will rip our family apart," she said with tearful eyes.

READ MORE: Immigration ban - Hope trumps fear for Iranian Americans

It is unbelievable. I had visited the US during the worst times between Iran and America. I never imagined that after the nuclear deal the situation will get worse! Mahmoud Kashani, a factory owner

Iranians have traditionally built a sizable community in the United States. For decades, the US has been the number one destination for thousands of Iranian citizens seeking better educational and job opportunities.

US Department of State issues approximately 35,000 visas for Iranians annually, including student and tourist visas. Since there are no diplomatic relations between Iran and the US, Iranians apply through various US consulates in the region. The exact number of visas issued is, therefore, hard to work out.

According to the Public Affairs Alliance of Iranian Americans,1.5 million Iranians lived in the US in 2012. In 2003, Iran's Interests Section in Washington said that it held passport details of 90,0000 Iranians living in the US.

High-profile citizens from the Iranian American community have included Firouz Naderi, a senior NASA director; Bijan, the late fashion icon; Pierre Omidayr, the eBay founder; Omid Kordestani, executive chairman at Twitter and Salar Kamangar, a senior executive at Google, to name but a few.

According to a report by the Iranian Medical Society, as of 2013, 5,050 physicians and medical university graduates have ended up in the US.

Mahmoud Kashani, 68, is a factory owner who regularly visits the US for business and to visit with his two sons who have been studying there for many years, is still shocked by the news.

"It is unbelievable. I had visited the US during the worst times between Iran and America. I never imagined that after the nuclear deal the situation will get worse!"

Kashani says he had hoped that the landmark nuclear deal would further ease tensions between Iran and the US. "I have my multiple entry visa and was about to book a ticket for [Persian New Year] to the States, but it is vaporised now and gone into the air!"

Iranian Oscar-winning director Asghar Farhadi, whose new film, The Salesman, has been nominated for best foreign language feature length movie, issued a harshly worded letter on Sunday and said he would not attend the academy award ceremony.

"I express my criticism of the unjust conditions enforced on some of my compatriots and the citizens of the other six countries who were going to legally enter the United States of America and hope that the current situation will not give rise to further rift between nations," wrote Farhadi.

READ MORE: Trump's Muslim ban - This could never happen in America

Saeed's sister, Elham Qurbani, 30, says she had initially planned to apply for a US student visa and join her brother, but was advised by her immigration lawyer that the chances were not good.

"I feel pity for my mom and dad to go through such pain and anxiety," said Qurbani who is about to leave for Australia on a student visa next week.

She recounted the story of their neighbour, whose son, Vahid, has been studying in a North Carolina State University and wanted to return home after seven years.

"Two weeks ago, his mother was so excited that she will see her youngest son after a long time! Now, I don't know how she feels!"

"It is ridiculous that highly educated Iranians are barred from travelling to the US, but some countries with the worst records of violations are not!"

Meanwhile, Nayereh says she spoke with her son on Saturday night and urged him not to risk his situation -still being a green card holder - in the US by travelling.

"Saeed told me that the news was shocking and that he was feeling as if he is locked up in a prison; beautiful and green, but still feels like a prison."