"We are demonstrating the power of American strength and diplomacy. We're upholding the principle that bigger nations can't bully the small - by opposing Russian aggression, supporting Ukraine's democracy, and reassuring our NATO allies," he said.
"Last year, as we were doing the hard work of imposing sanctions along with our allies, some suggested that Mr. Putin's aggression was a masterful display of strategy and strength. Well, today, it is America that stands strong and united with our allies, while Russia is isolated, with its economy in tatters," the U.S. president said.
Earlier, U.S. President Barack Obama and French President Francois Hollande held a telephone conversation during which they agreed on the need to maintain sanctions against Russia, in case if there is no progress in the implementation of the Minsk agreements.
In addition, the two leaders advocated the importance of providing additional financial support to the Ukrainian government.