Putin is now betting that sky-rocketing energy prices and possible shortages this winter will persuade Europe to strong arm Ukraine into a truce - on Russia's terms

This is the only path to peace Moscow sees, two Russian sources told Reuters, as the Ukrainian side says it will not negotiate until Russia leaves all of Ukraine.

"We have time, we can wait," said the Russian representative on condition of anonymity.

"The winter will be difficult for Europeans. We saw protests, unrest. "Some European leaders may think twice about continuing to support Ukraine and think it's time for a deal," the Russian representative said.

A second source close to the Kremlin said Moscow thought it could already detect faltering European unity and expected that process to accelerate amid winter hardship.