The Biden administration has information indicating Russia might soon launch a false-flag operation to provide a pretext for an invasion of Ukraine, a U.S. official told Politico.

Per the official, Russia has already placed a group of operatives “trained in urban warfare and in using explosives” in eastern Ukraine. The intel suggests that this group might “carry out acts of sabotage against Russia’s own proxy-forces,” thereby providing the Kremlin a convenient excuse to send some or all of its 100,000 troops stationed outside of Ukraine over the border.

The Russian military plans to start these activities “several weeks” before a potential invasion, which is estimated to begin sometime between mid-January and mid-February, the official continued. “We saw this playbook in 2014 with Crimea.”

CNN first reported on the obtained intelligence.

Top U.S. officials, including national security adviser Jake Sullivan and Secretary of State Antony Blinken, in recent days previewed that the U.S. had information suggesting that Moscow was setting the groundwork for another incursion.

“Russia is laying the groundwork to have the option of fabricating a pretext for an invasion, including through sabotage activities and information operations, by accusing Ukraine of preparing an imminent attack against Russian forces in Eastern Ukraine,” Sullivan told reporters at the White House Thursday, promising the administration would share more details within the following 24 hours.

Read more: Politico