The proposal was set out in a document published by the Washington Post. It will be presented by US Secretary of State John Kerry during a visit to Moscow Thursday, the newspaper reported.
"Once we have received these proposals from the original source and not from a newspaper, then we will be able to say something," Kremlin spokesman Dmitry Peskov told a conference call with journalists as cited by Reuters.
He said Kerry would hold talks with Russian President Vladimir Putin late Thursday and with Russian Foreign Minister Sergei Lavrov Friday.