The Kremlin failed to give an explanation to the U.K. about how a nerve agent was used to attack a former Russian spy and his daughter in Salisbury, a move which could prompt a strong retaliation from the British government.
Prime Minister Theresa May is expected to make a statement to the U.K.'s parliament on Wednesday afternoon, outlining what measures the country intends to take against Russia.
Russia was given until midnight on Tuesday to explain to the U.K. government why a nerve agent — one of the "Novichok" family of deadly chemical weapons developed in Russia — was used to poison former Russian secret service agent Sergei Skripal and his daughter Yulia in Salisbury in early March.
But Moscow has so far not provided any official explanation for the attack although Foreign Minister Sergei Lavrov said Tuesday that Russia was not involved and "had not been given access to materials" related to the case, Reuters reported.
On Wednesday morning, Kremlin spokesman Dmitry Peskov again reiterated that Russia had no involvement in the poisoning and said the accusations were "baseless."
Asked about possible British measures against Russia, he said the Kremlin hoped common sense would prevail and that it was too early to say what Russia's response to any measures might be.
Despite the Kremlin's insistence otherwise, the investigation still points to Russia's involvement — Skripal was a former Russian spy turned double agent for the U.K. — May said Monday that it was "highly likely" that Russia was responsible for the attempted murders. The Skripals remain in a critical condition in hospital.