The United States sees all signs that Russian President Vladimir Putin is going to use military force against Ukraine, U.S. Under Secretary of State Wendy Sherman said.

"I have no idea whether he is [Putin] made the ultimate decision, but we certainly see every indication that he is going to use military force sometime perhaps (between) now and the middle of February," Sherman said during the online discussion organized by the Victor Pinchuk Foundation on Wednesday.

She said the opening ceremony of the Beijing Olympic Games will take place on February 4, and President Putin will attend, which could influence his decision-making.

"I don't know what's in President Putin's mind. There is only one person who knows this and that is President Putin. I suspect that even the people around him don't know what he will ultimately do. I think they know plans for military readiness, plans for using the military, but I suspect the president has other plans in mind as well," Sherman said.