Nigerian Nobel laureate Wole Soyinka says the United States (US) has revoked his visa and barred him from entering the country, a move he linked to his long-standing criticism of President Donald Trump.

Speaking at a press conference in Lagos this week, the 91-year-old author said the US consulate had requested his passport so that his visa could be formally cancelled, citing new, unspecified information. "I received what I can only describe as a rather curious love letter from an embassy," Soyinka said. "I have no visa. I am banned."

Soyinka, who won the Nobel Prize for Literature in 1986, has held teaching appointments at American universities for more than three decades. He once held permanent residency but renounced his US green card in 2016, tearing it up in protest after Trump’s election. On Tuesday, he joked that the card: "fell between the fingers of a pair of scissors and got cut into a couple of pieces."

The writer suggested his recent comments comparing Trump to Uganda’s late dictator Idi Amin may have prompted the US decision. "When I called Donald Trump Idi Amin, I thought I was paying him a compliment," Soyinka said, adding that Trump: "has been behaving like a dictator."

The US embassy in Nigeria said it could not comment on individual cases. The revocation follows the US State Department’s July decision to sharply curtail non-immigrant visas for Nigerians and citizens of several other African countries.