Kukliński, who died 14 years ago and was later posthumously promoted to general, was on Sunday remembered in Kraków and Gdańsk as well as at a military cemetery in Warsaw, where he is buried.
The Speaker of the lower house of Poland’s parliament, Marek Kuchciński, wrote a letter to those attending the Warsaw ceremony to say that Kukliński was a man who served his country when it was under Soviet control during the communist era.
Kukliński passed top-secret Warsaw Pact documents to the CIA between 1971 and 1981, including plans for a military onslaught on the West and for the imposition of martial law in Poland to crush the Solidarity movement.
Shortly after the declaration of martial law in December 1981, Kukliński was extracted from Poland by the CIA, along with his family.
In 1984, a military court in Warsaw sentenced him to death in absentia. The sentence was annulled after the fall of communism in Poland in 1989.
Kukliński died in the United States on February 11, 2004 at the age of 73.
He was posthumously elevated to the rank of brigadier general by Polish President Andrzej Duda in 2016.