Much work remains, says Vladimir Putin's spokesman Dmitry Peskov.
Peskov says the talks may not be friendly, but they have begun in a "constructive" spirit.
Russia has repeatedly referred to Putin's meeting with Donald Trump in Alaska this summer. According to Russian statements, the presidents agreed on a framework, and media reports say it concerns Russia's demand for the entire Donbas region of Ukraine.
Dmitry Peskov also refers to the alleged framework and emphasizes that "the territorial parts" of it are of crucial importance for Russia.
