MOSCOW, March 19. /TASS/. London will sooner or later have to either furnish evidence to sustain its allegations against Moscow over the poisoning incident of former spy Sergei Skripal and his daughter Yulia, or apologize, Kremlin Spokesman Dmitry Peskov told reporters.

"Sooner or later they will have to be responsible for these allegations: they will either have to provide some evidence or apologize," Peskov said, noting that the UK’s accusations against Russia are difficult to explain.

Peskov refused to call this situation "a deterioration of relations with the West," noting that the UK leadership’s accusations against Russia are difficult to explain and the motivation for the slander was unclear.

On March 4, ex-intelligence officer Sergei Skripal and his daughter Yulia were found unconscious on a bench near the Maltings shopping center in Salisbury after being exposed to a nerve agent. Both are in hospital in critical condition.