Ukraine and Western governments want Russia to agree to an immediate, unconditional ceasefire lasting at least 30 days, but a Ukrainian source said Russia's demands were too much.

* International recognition that five parts of Ukraine -- the Crimea peninsula annexed in 2014, as well as the Donetsk, Luhansk, Kherson and Zaporizhzhia regions -- are Russian. The U.S. draft had proposed only U.S. de jure recognition for Crimea, and U.S. de facto recognition for Russian-controlled parts of the other regions.

During the talks on Friday in Istanbul, Russia presented Ukraine with a series of conditions that must be met before a ceasefire can occur. Among them, the Kremlin includes the recognition of the annexation of Crimea and other regions and the adoption of a neutral status - Bloomberg reported on Saturday.