An agreement on settling the crisis in Ukraine envisions a parliamentary vote on constitutional amendments in September and presidential elections in December 2014, Party of Regions parliamentary faction leader Oleksandr Yefremov said.

"The agreement that was drawn up last night will be initialed at noon. Then, within this framework, it will be signed by the president and the opposition and will supposedly be initialed by France, Germany, Poland, and Russia," Yefremov told Interfax-Ukraine on Friday morning.

"Within 48 hours after signing this agreement, a bill should be drawn up to reinstate an earlier version of the constitution, either the 2004 version or it's being mulled now that it's going to be Musiyaka's constitution," Yefremov said, referring to Viktor Musiyaka, an author of the 1996 version of the Ukrainian constitution.

"Then a voting procedure for amendments to the constitution will be drawn up […] and the voting on this constitution will be scheduled for September, and if the voting on the constitution is in September, then presidential elections will be in December," Yefremov said.