() Russian President Vladimir Putin’s suggestion Thursday he supports a ceasefire with Ukraine comes with many caveats that could scuttle a peace deal, former NATO Supreme Allied Commander Europe Wesley Clark says.

Ukrainian leaders have already agreed to a 30-day halt in fighting, and now, U.S. representatives are seeking Russia’s acceptance so that talks for lasting peace can begin in earnest. Putin said he supports the ceasefire in concept but said any permanent solution must address the “root causes” of the conflict.

“What’s the root cause? The root cause is Ukraine wants to be aligned with the West. It wants protection from Russian interference,” Clark told “ Now.”

Putin would like to roll back NATO and absorb additional close neighbors such as the Baltic states and Bulgaria, the retired U.S. Army general said.

He predicted Putin may take part in negotiations while trying to maintain the upper hand militarily.

“It’s talk, talk, fight, fight,” Clark said.

Putin has limits: Ex-ambassador

Vladimir Putin is a former KGB official who knows how to manipulate people, says John Herbst, the former U.S. ambassador to Ukraine under President George W. Bush. Herbst told “Elizabeth Vargas Reports” that Putin will try to manipulate President Trump if Ukraine peace talks move forward.

“Of course he can’t be trusted,” Herbst said of Putin. “And he’s demonstrated that over the past 20 years, breaking multiple treaties, breaking multiple commitments.”

And yet Putin realizes he cannot be seen as double-crossing Trump, the former ambassador said.

“I would not dismiss the idea that Putin has a certain wariness with Trump,” Herbst said. “He believes he’s able to persuade him, but he also understands, I think, that if he crosses Trump and Trump understands that, that can be very bad for Putin and for Russia.”