"He will probably spend the holidays in the hospital under doctors' care," the writer and film and theater director told BNS.
He said that his father was in stable condition in Vilnius' Santaros Clinic.
Landsbergis on Feb. 16 every year makes a speech from the balcony of the House of the Signatories in downtown Vilnius where the Council of Lithuania signed the Act of Independence on Feb. 16, 1918.
This year, his speech will be read out by actor Rimantas Bagdzevičius, his son said.
Landsbergis, 85, was Lithuania's top-ranking official when the country declared independence from the Soviet Union in 1990, significantly contributing to the collapse of the Soviet Union.
He presided over the Supreme Council when it adopted the Act of the Re-Establishment of the State of Lithuania on Mar. 11, 1990. Under his leadership, Lithuania managed to withstand the Soviet Unions' economic blockade and gained international recognition.