(Reuters) – Russian President Vladimir Putin told his Finnish counterpart Sauli Niinisto on Saturday that ditching neutrality and joining NATO would be a mistake that could damage relations between their two countries, the Kremlin said. The two countries said their presidents spoke by phone two days after Finland declared its intention to join the Western alliance. Moscow has described that as a security threat that will require it to respond, but has not specified how. Niinisto’s office said he told Putin “how fundamentally the Russian demands in late 2021 aiming at preventing countries from …