The father of ailing twin girls both in need of a new liver is undergoing surgery today at Toronto General Hospital in an effort to save one of their lives.

Michael Wagner's three-year-old daughters, Phuoc and Binh, have been diagnosed with Alagille syndrome, a genetic condition that affects the liver, heart and other organs. Without a liver transplant, the girls will not survive.

The Kingston parents previously told The Canadian Press that they asked doctors to decide which of the twins would receive their father's liver because they said they were unable to choose.

While Phuoc will soon be receiving a new liver from her father, a donor has not yet been found for Binh, Suzanne Gold, a spokesperson with the Hospital for Sick Children, told CTV News in a written statement.

Wagner's surgery will take place at Toronto General Hospital and his daughter's surgery will be performed at the Hospital for Sick Children, Gold said. The surgeries are expected to take a total of 18 to 22 hours.

Gold said that an update will be provided at a news conference on Thursday.