Sanctions against Russia over the non-compliance with the Minsk agreements are working, U.S. Assistant Secretary of State for European and Eurasian Affairs Victoria Nuland has said.

"These sanctions, combined with low oil prices and Russia's continued structural weaknesses, have imposed significant costs. While Moscow has not yet changed its approach to Ukraine, our readiness to toughen sanctions even further has likely played a role in deterring further Russian efforts to grab Ukrainian territory," Nuland said at the Senate Foreign Relations Committee hearing on Tuesday.

In her words, the U.S. is now working intensively with Europe to ensure EU sanctions are rolled over at the end of this month, and to support France and Germany in their lead diplomatic role to push for full implementation of the Minsk agreements.