A new classified intelligence assessment concludes it is more likely than previously thought that Russian forces will enter eastern Ukraine, CNN has learned.

Two administration officials described the assessment but declined to be identified due to the sensitive nature of the information.

The officials emphasized that nothing is certain, but there have been several worrying signs in the past three to four days.

“This has shifted our thinking that the likelihood of a further Russian incursion is more probable than it was previously thought to be,” one official said.