Lukashenko did not mention the name of the former Mossad chief at a news conference Tuesday but Israeli media reports identified him as Meir Dagan, 67.
Lukashenko said the transplant was carried out by local doctors after U.S., Swedish and German doctors refused to perform the operation, Maariv said Wednesday. The president said he was consulted prior to the operation and while "no promises could be guaranteed to the outcome, we will do our utmost to ensure the most advanced technologies are used," Lukashenko said.
Associates close to Dagan said no request was submitted to Sweden, and because of his condition, Dagan was found to be unsuitable for a transplant in the United States. He was advised to contact the Belarus Transplant Center in Minsk, Yedioth Ahronoth said.
The paper said Dagan was in an intensive care unit. His condition was described as critical but stable. The Israeli Embassy when contacted by Yedioth said diplomats had no knowledge of the operation.
Dagan served as head of the Mossad for two terms. He stepped down in 2011.