Russian lawmakers say they plan to submit a bill to parliament that would make it easier for new territories to join the Russian Federation.
Mikhail Yemelyanov, a leader of the A Just Russia party, said the move was necessary because of the "unpredictable" situation in Ukraine.
He said that, under the proposed bill, a territory would be able to join the Russian Federation on the basis of a referendum or a decision of its parliament.
Russia's "Kommersant" says that, currently, a foreign country or part of it can join the Russian Federation "with the mutual consent of the Russian Federation and this foreign state," confirmed by an international treaty.
Russia still considers Viktor Yanukovych, who was ousted as president by parliament on February 22, to be Ukraine's legitimate leader.
Yanukovych is currently in Russia.
Based on reporting by Interfax and ITAR-TASS