Ukraine accused Russia on Tuesday of moving tanks and extra sniper teams to the frontlines of the conflict in eastern Ukraine, ready to inflict fatalities on Ukrainian forces and incite retaliation.

Ukraine’s defense ministry released the statement only hours before US President Joe Biden and Russian President Vladimir Putin hold a high-stakes video chat following Russia’s massing of soldiers near Ukraine’s border.

According to the statement, “the adversary raised the number of sniper pairs in preparation to inflict fatalities on Joint Forces members, destroy video surveillance devices, and trigger back fire.”