US to expand list of Russians facing sanctions - White House

The U.S. authorities are working to expand the list of Russians facing asset freezes and travel bans due to the annexation of Crimea, White House spokesman Jay Carney told reporters on Tuesday.

"More is coming. Work is being done to make further designations [under the sanctions]," he said.

Carney declined to disclose details of the planned measures and did not say when they could take effect.

"If Russia refuses to change course, it will incur more costs, imposed by us, imposed by our friends and allies around the world and imposed in general by the global economy," he said.

Carney added that the United States would never recognize the results of the referendum on the status of Crimea.