Nigeria's Nobel Prize-winning author Wole Soyinka said on Tuesday the United States had revoked his non-immigrant visa issued last year and he was told to re-apply if he wished to try again to visit the U.S.

The 91-year-old writer said in 2016 that he had torn up his U.S. green card and renounced his American residency in protest at the first election of President Donald Trump.

The Nobel laureate has had regular teaching stints at America's Ivy League universities since the mid-1990s following his Nobel Prize for Literature in 1986.

On Tuesday, Soyinka showed reporters a copy of a letter from the U.S. Consulate General in Lagos asking him to bring his passport for physical cancellation of the visa.

The letter, dated October 23, said "additional information became available" after the visa was issued.

The U.S. Embassy in Nigeria did not immediately respond to a request for comment.

"I have no visa, I am banned obviously from the United States and if you want to see me, you know where to find me," he said, referring to people who planned to invite him to events in the U.S.

The U.S. Embassy in Nigeria said in July that Nigerians seeking to travel to the U.S. on non-immigrant visas would now receive single-entry three-month permits, rolling back the up to five-year, multiple-entry visas they had enjoyed previously.