The European Union has urged Turkey to let Syrian refugees cross the border.
35,000 refugees have fled the fighting in Aleppo.
Regime forces and Russian jets have launched an offensive against rebel groups.
EU Foreign Policy chief Federica Mogherini said Turkey has a moral and legal duty to help.
Turkey says there is no need for the refugees to cross the border. They'll be given food and shelter on the Syrian side.
The fighting in Aleppo is intense. It might tip the balance in the regime's favor.
The war in Syria has killed 250,000 people. 11 million displaced.