In a condolence message sent to Russian President Vladimir Putin, Assad said the two countries were partners in the "fight to lay the foundations of stability, security and peace" in Syria. Russian-backed government forces ousted the last rebels from the city of Aleppo on Thursday after years of fighting.
The Russian TU-154 plane carrying 92 people, including dozens of Red Army Choir singers, dancers and orchestra members, crashed into the Black Sea on its way to Syria on Sunday, killing everyone on board, Russian authorities said.