The announcement appeared to be part of Moscow’s efforts to counter Western warnings of a Russian invasion and paint Ukraine as the aggressor instead.
The strong showing reflects the public longing for a fresh leader who has no links to the corruption-ridden Ukrainian political elite.
Russia's ambassador revealed the discussions amid confusion in the U.S. about what the two presidents agreed behind closed doors.
Eastern Ukraine is experiencing heavy fighting between its army and pro-Russia separatists.
A new bill would require congressional oversight for changes.