In a letter it issued late Tuesday, the PEN American Center is asking the government to revisit its decision to block Bulgarian-German author Ilija Trojanov, who is a vocal critic of the United States government’s surveillance programs, from entering the country. The letter was sent to Secretary of State John Kerry and Acting Secretary of Homeland Security Rand Beers, regarding a decision that came down on September 30.

Trojanov, PEN said, was stopped at an airport in Brazil on his way to the U.S. by border crossing security. In a release about the situation, PEN said he was “then refused entry [on his connecting flight] without further explanation and told to fly back to Germany.”

The government’s refusal to allow Trojanov in the country is, PEN explained, something that “calls to mind our country’s checkered history of barring writers whose political views it disfavors, at a time when the need to model tolerance for dissent is stronger than ever.”

Trojanov is a member of the German PEN Center, and has written over 20 books, including the 2009 book about government surveillance, Angriff auf die Freiheit (Attack on Freedom). He was born in Bulgaria in 1965 and fled the country in 1971, with his parents, latering obtaining political asylum in Germany. With author Juli Zeh, he co-wrote an open letter to German Chancellor Angela Merkel, in July, asking her to respond to the NSA’s surveillance program in the States.