Nato has called for Russia to disclose its Novichok nerve agent programme to international monitors, following the poisoning of activist Alexei Navalny. Secretary General Jens Stoltenberg said members were united in condemning the "horrific" attack. He added there was "proof beyond doubt" that a Novichok nerve agent was used against Mr Navalny. But Russia has dismissed the diagnosis given by doctors in Germany, where he is being treated. Speaking after an emergency Nato meeting, Mr Stoltenberg said the Kremlin "must fully co-operate with the Organisation for the Prohibition of Chemical Weapons on an impartial international investigation". "We also call on Russia to provide complete disclosure of the Novichok programme to the OPCW," he added.