Petro Poroshenko wrote Facebook, Censor.NET reports.
"It is sad, but Zbigniew Brzezinski, Grand Master of international politics, a legend, and an epoch, passed away. A true friend Ukraine departed! I express my sincere condolences to friends and relatives of Brzezinski. May the memory of him live forever!," Poroshenko wrote.
Brzezinski died at a hospital in Falls Church, Virginia, at the age of 89 on May 26.
Zbigniew Brzezinski was a Polish-American diplomat and political scientist. He served as a counselor to President Lyndon B. Johnson from 1966 to 1968 and was President Jimmy Carter's National Security Advisor from 1977 to 1981.