Sergey Lavrov says Moscow was not responsible for the nerve agent attack on a former Russian spy in the UK earlier this month. Instead, the Russian foreign minister blamed Britain for not giving it access to the materials related to the attack. The British government, however, continues to point the finger at the Kremlin, with Prime Minister Theresa May saying it was "highly likely" Russia was involved in the poisoning. Meanwhile, as a potential diplomatic crisis between the pair unfolds, both countries have summoned their respective ambassadors for further explanations.