WASHINGTON, May 6 - The Obama administration is working on new sanctions that would be imposed on Russia if it dramatically ramped up aggression against Ukraine, such as preventing elections from taking place in much of the country or recognizing another separatist referendum, U.S. officials said on Tuesday, Reuters reported.

"What we're doing this week ... is trying to develop this strong sectoral package on both sides of the Atlantic so that the Russians can see it, understand it, and understand its impact if they take further action to prevent these elections from happening," Assistant Secretary of State Victoria Nuland told a Senate Foreign Relations Committee hearing.