Tommy Robinson will speak at a US event by video link because his visa application was reportedly not granted in time.
The former head of the English Defence League was due to meet Republican politicians in Washington this week at the invitation of the Middle East forum.
But he was not granted a visa in time for the meeting, according to Daniel Pipes, president of the conservative Philadelphia-based organisation, Reuters reported.
Robinson, a right-wing activist, denied his visa application had been rejected and described reports as “fake news”.
And the Middle East Forum said that Robinson’s visa had not been denied but was going through “administrative processing”.
Executive liaison Lisa Barbounis said Robinson would join Wednesday’s event, hosted by Arizona Republican Congressman Paul Gosar, via video link.
She said: “It wasn’t denied [his visa], it has been reviewed for administrative processing.
“He has other invitations to speak later in the year and isn’t worried about rushing to do the event because we can do a longer tour later.”
But US sources told the Press Association that Robinson’s application had been denied – though he had the opportunity for further review.
Administrative processing is when an application is sent for further screening and evaluation, and can be expected to take up to 60 days.
However the US Embassy in London’s website says it can take more than six months.
Robinson, whose real name is Stephen Yaxley-Lennon, is currently barred from the US after attempting to enter the country using a friend’s passport in 2012.
He was blocked from travelling under standard arrangements because of “multiple criminal convictions, including several for violent conduct and assault as well as mortgage fraud”.
Last month, Robinson told Sky News he does not care whether his message “incites fear” of Muslims as long as it “prevents children from getting raped”.
The English Defence League founder spoke about being found guilty of contempt of court in May last year for trying to film and expressing views about suspects in a sexual grooming case in Canterbury.
He said: “If I believe I’m morally right then I’m not bothered about what your law says.”
Robinson was released from prison in September after three leading judges quashed a finding made at Leeds Crown Court in May, and granted him conditional bail from a 13-month jail sentence.
(c) Sky News 2018: Tommy Robinson to speak at US event via video link amid ‘visa delays’