An unexpected move by Russia's central bank to cut its main interest rate shows continued chaos in the country's economy, some of it due to Western sanctions related to the Ukraine crisis, a White House spokesman said Friday.

"There are specific and clear economic costs associated with President (Vladimir) Putin's expedition into eastern Ukraine," spokesman Josh Earnest told a daily briefing.

"We're hopeful that as these costs mount it will prompt president Putin to re-evaluate his strategy," Earnest added.