Geneva-born Muslim scholar Tariq Ramadan has said he is “in shock” that he will not be able to take up a teaching post in the United States after his visa was revoked.
The US State Department said it had cancelled the visa at the request of the Department of Homeland Security.
Ramadan – who was granted the visa in February – had been due to start teaching at Notre Dame University in Indiana next week.
“All our affairs are already in order in the US. My children are registered in American schools. I’m in shock,” he said.
On Wednesday he told swissinfo that he had appealed to the Swiss authorities to put pressure on Washington to reverse its decision.
“[Swiss Foreign Minister] Micheline Calmy-Rey has personally intervened, through the US embassy in Bern, to get an explanation,” he said.
“If the American administration realises that this file was badly managed, I am hopeful that it will quickly reconsider its decision,” he added.
The Swiss foreign ministry confirmed that it was providing Ramadan with “consular support”, but spokesman Christian Meuwly declined to give further details.
Russ Knocke, a Department of Homeland Security spokesman, said Ramadan’s work visa had been revoked because of a section in federal law applying to foreigners who have used a “position of prominence within any country to endorse or espouse terrorist activity”.
He added that the cancellation of the visa was based on “public safety or national security interests”.
A recognised authority on the place of Islam in Europe, Ramadan has been teaching in Geneva and at Fribourg University.
He has gained a popular following among European Muslims, showing how Islamic values are compatible with those of secular European society.
But he has been criticised for alleged links to Islamic militants and was branded an anti-Semite after he accused French-Jewish intellectuals of supporting the war in Iraq to bolster Israel’s interests – despite having publicly taken a position in the past against anti-Semitic acts.
The 41-year-old Ramadan described the decision to revoke his visa as “unjustified” and said he had been through a rigorous two-month background check before he was given the relevant papers.
“If I had had illicit and suspect activities, why would I settle in the United States, with all the police checks in place there?” he asked.
“As a Muslim, when I criticise a policy of, for example, Saudi Arabia or Egypt, I am not Islamophobic. And when I criticise the policy of the state of Israel, I'm not an anti-Semite. It's just political criticism.”
Notre Dame spokesman Matt Storin said the university stood behind its decision to offer Ramadan a teaching post.
“We absolutely don't agree with [the decision to revoke his visa]. If we did, we would not have hired him,” said Storin, who described Ramadan as a distinguished scholar and a voice of moderation in the Muslim world.
Ibrahim Hooper, spokesman for the Council on American-Islamic Relations, said the decision to cancel Ramadan’s visa showed an unwillingness on the part of the United States to listen to Muslims.
“It's really a slap in the face to Muslims who are trying to build bridges between the Muslim world and the West,” Hooper said.
But Yehudit Barsky of the American-Jewish Committee claims that Ramadan is trying to bring legitimacy to Islamic militants.
“We really had hoped the university would have exercised more caution in bringing him over here,” she said in a recent interview.
Notre Dame, a Catholic university, appointed Ramadan to its Kroc Institute for International Peace Studies earlier this year to take up a post as professor of religion, conflict and peacebuilding.
swissinfo, Elizabeth Meen
Tariq Ramadan has been stripped of the visa he needs to teach in the United States.
US officials say the move was based on "public safety or national security interests".
Ramadan, a Swiss university lecturer, was born in Geneva in 1962 and is married with four children.
Tariq Ramadan has been teaching in Geneva and at Fribourg University.
He has gained a popular following among European Muslims, showing how
Islamic values are compatible with those of secular European society.
He has called for a moratorium on stoning and says women should decide for themselves on whether to wear a veil.