The White House is declining to say whether it plans to impose sanctions directly on Russian President Vladimir Putin if he does not back down and pull troops out of Ukraine's Crimea region.

President Obama on Thursday issued an executive order readying sanctions on Russia to include freezing individual Russians' overseas assets and put a ban on visas to the United States.

White House press secretary Jay Carney and other senior administration officials said the action only provided the framework for sanctions and Russia still had time to de-escalate the crisis.

Under repeated questioning about whether the administration plans to level sanctions against Putin, Carney said only that he was not ruling any particular person in or out.

“No Russian individuals or entities are blocked pursuant to the executive order,” he said. “It provides a flexible tool that in the coming days and weeks can be used to sanction persons. ... The authority has been granted, broad authority has been granted, to issue those sanctions as appropriate.

He later added that determinations about who to target would be made “as we evaluate the situation on the ground.”