Russia may deploy its military to police the borders of planned de-escalation zones in Syria within two to three weeks after finalizing an agreement with Turkey and Iran, Russian negotiator Alexander Lavrentyev said on Tuesday.

Moscow hopes to sign the final documents with Ankara and Tehran on Wednesday, he told reporters after a series of meetings in the Kazakh capital, Astana.

Russia and Iran, which back President Bashar Assad's government, and Turkey, which supports some of the rebels, agreed in principle to create four de-escalation zones in Syria in a round of talks in May but put off a planned June meeting at which they were supposed to work out the details.