U.S. President Barack Obama signed a bill authorizing new sanctions against Russia on December 18 but said that he would not impose them "at this time."
The Ukraine Freedom Support Act authorizes -- but does not technically require -- defensive lethal aid for Kyiv and sanctions against Russian defense and energy sectors.
Obama said in a statement that the signing of the legislation "does not signal a change in the administration's sanctions policy."
Sanctions, along with plummeting oil prices, have contributed to Russia's economic turmoil, as well as the fall of its currency.
The bill passed the divided U.S. Congress unanimously.
The bill also authorizes more loan guarantees for Ukraine and additional funds to address the country's energy shortage, for U.S. international broadcasting, and for Russian democracy and civil society organizations.