Russia is threatening to use its veto power at the United Nations Security Council to shut a critical aid corridor into northern Syria.
The Bab al-Hawa border crossing is the only point of entry for humanitarian supplies from Turkey.
The Security Council is expected to vote on whether to reauthorise its use later on Thursday.
At least three million people rely on humanitarian deliveries made through the crossing.
Al Jazeera's Sinem Koseoglu has more from Istanbul.

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