A supply of U.S. Tomahawk cruise missiles to Ukraine could help "push Russia back," Margus Tsahkna -- the foreign minister of NATO ally Estonia -- told ABC News, after U.S. President Donald Trump said he had "sort of made a decision" on whether to green-light the long-range weapon for Ukrainian use.

Rosenergoatom, which operates the nuclear plant, said this was "yet another act of aggression by the Ukrainian Armed Forces"