His daughter, Mika Brzezinski, co-host of MSNBC's "Morning Joe," announced her father's death on social media. She did not give a cause of death.
"He was known to his friends as Zbig, to his grandchildren as Chief and to his wife as the enduring love of her life," she said in a post on Instagram.
Brzezinski, who was Polish born, served as Carter's national security advisor during the Iran hostage crisis and the Soviet invasion of Afghanistan. He helped Carter bridge the gap between Israeli Prime Minister Menachem Begin and Egyptian President Anwar Sadat to the Camp David peace accords.
Carter and his wife Rosalynn expressed their condolences, calling Brzezinski "an important part of our lives for more than four decades" and "a superb public servant."
"He played an essential role in all the key foreign policy events of my administration, including normalization of relations with China, signing of the SALT II treaty, brokering the Camp David Accords, and the Panama Canal treaties, among others," Carter said. "He was brilliant, dedicated, and loyal, and remained a close advisor to my work at The Carter Center. I will miss him."
Among his other accomplishments, Brzezinski was awarded the Presidential Medal of Freedom by Carter in 1981 for working to normalize relations between the United States and China and for his work to advance human rights.