President Barack Obama believes a peace deal reached last year between Russia and Ukraine can be implemented before he leaves office in January, AFP reports.
The Minsk accord -- signed in February 2015 with French and German mediation and in the presence of President Vladimir Putin -- calls for a ceasefire along with a range of political, economic and social measures to end the conflict in eastern Ukraine.
"This is something that could get done between now and the end of the administration, if the Russians in particular exhibit sufficient political will," Susan Rice, Obama's national security advisor and the former US ambassador to the United Nations, said in a discussion hosted by the Washington Post.
"We are hopeful that if the Russians want to resolve this -- and we have some reason to believe that they might -- that we have the time and the wherewithal and the tools to do so," she added.
Relations between the United States and Russia have been fraught since Russia annexed Crimea in 2014 and subsequently helped fuel a pro-Russian separatist conflict in eastern Ukraine.