BOSTON (AP) — Harvard Medical School researchers say they're frustrated that President Donald Trump's travel ban is keeping bright new Iranian recruits from joining them in Boston.

Professor Thomas Michel says he initially was so excited about hiring Iranian national Soheil Saravi, he put Saravi's name on the door of his lab.

But Saravi hasn't been allowed to enter the U.S., even though he has a visa allowing him to work in the country.

Trump's ban on people from Iran and six other predominantly Muslim countries has angered academics like Michel.

They note that Boston and other U.S. cities long have prided themselves on attracting the world's best and brightest.

The Trump administration insists the order is necessary to keep potential terrorists out of the country until security procedures are improved.