Reports of Russian military buildup near the Ukrainian border are no cause for alarm, given that Russia does not pose any threat to Ukraine or any other country.
Russia's army manoeuvres are indeed a cause for concern, particularly given the recent flare-up of armed hostilities between Ukraine and the Russia-backed militants in the occupied Donbas. See here for detailed debunking by POLYGRAPH.info.
It is also worth remembering that Russia's actions against Ukraine have, in recent years, gone well beyond threats. Moscow has waged large-scale armed aggression against Ukraine, beginning in 2014 with the illegal annexation of Crimea and an undeclared armed conflict in the east of the country which has claimed 13,000 lives to date.