Russian president Vladimir Putin has criticised a decision to prevent some of the country's athletes from competing at the Olympics.

He has called the ban on track and field competitors "discrimination" and a political campaign against Russian sportspeople.

Putin was addressing the country's Olympic team at the Kremlin, and claimed the absence of some stars at the Games would affect the quality of the competition.

Putin, who his honorary president of the International Judo Federation which is allowing Russian competitors, added that the ban on other athletes "does not only go beyond the legal sphere, it goes beyond common sense".