The United States has revealed it fears Russia is prepping for an invasion of Ukraine, warning a war could be on the horizon

The warning comes as Ukraine revealed it has evidence that Russia was behind a cyberattack that defaced its government websites, with the nation claiming that Moscow is engaged in an increasing “hybrid war” against it.

That disclosure suggested the attention-grabbing defacement attack on official websites last week was a diversion.

White House press secretary Jen Psaki told reporters the United States was concerned that Russia was preparing for the possibility of a new military assault on a country it invaded in 2014.

“As part of its plans, Russia is laying the groundwork to have the option of fabricating a pretext for invasion, including through sabotage activities and information operations, by accusing Ukraine of preparing an imminent attack against Russian forces in eastern Ukraine,” Psaki said.

A U.S. official said the United States had information that indicated Russia had already positioned a group of operatives to conduct “a false-flag operation” in eastern Ukraine.