A cyberattack aimed at paralyzing banks and government websites was the worst of its kind in Ukrainian history, officials in Kyiv said, as the standoff with Russia continues to draw warnings of a potential invasion.

The DDoS, or distributed denial-of-service, attack began Tuesday and continued into Wednesday with the goal of causing mass confusion, Mykhailo Fedorov, Ukraine’s minister of digital transformation, said during an online briefing.

"This attack was unprecedented, it was prepared well in advance, and its key goal was destabilization, sowing panic and creating chaos in our country,” he said.