MOSCOW — A top Russian diplomat Thursday denounced British accusations that Russian military intelligence agents poisoned a former spy in England, calling them base untruths aimed at whipping up hostility toward Moscow.

The statement by Ambassador Vassily Nebenzia to a session of the U.N. Security Council came hours after Britain’s security minister said Russian President Vladimir Putin is ultimately responsible for the nerve-agent poisoning in March of Sergei Skripal and his daughter, Yulia, in the city of Salisbury.

Britain produced an “unfounded and mendacious cocktail of facts” and is refusing to cooperate with Russia in investigating the poisoning “to unleash a disgusting anti-Russian hysteria and to involve other countries in this hysteria,” Nebenzia said.

Moscow has denied involvement in the poisonings since the beginning of the case.

On Wednesday, Britain said it had identified two alleged agents of Russia’s GRU military intelligence service as suspects.

Earlier at the Security Council, Ambassador Karen Pierce of Britain accused Russia of failing to uphold the ban on using chemical weapons and playing “dice” with the lives of the people of Salisbury.

Pierce said the international community must take steps to safeguard people against the use of chemical weapons and “the threat of hostile foreign interference.”