De Mistura had previously said Aleppo would be a “good candidate” to become a “freeze” zone.
“Barrel bombs kill those we love most, they destroy houses, dreams and memories,” said a Syrian civilian.
“I recognize the contradiction in a contradictory land and a contradictory circumstance,” Obama said.
Last December, President Bashar al-Assad’s regime launched a massive aerial campaign against rebel districts.
President Hollande comments came after Assad’s regime said it was willing to work with the international community.
The opposition National Coalition branded the election a ‘farce’.
More than 162,000 people have been killed since Syria’s conflict began in March 2011.
The report comes amid fierce clashes on the outskirts of Damascus between the Islamic State of Iraq and the Levant, the Syrian Observatory for Human Rights said.
The Syrian Observatory for Human Rights said 37 people were killed, including civilians as well as security personnel, and more than 40 wounded.
The colonel said he had spoken with one of the kidnappers, who said those held “are safe with us,” and will be moved to a “safer place”.
Farce of Syrian presidential elections follows the tragedy of its civil war.
Foreign Secretary William Hague said Assad had no plan for peace, stability or reconstruction in Syria.
Bashar al-Assad has no more credibility today than he did yesterday,” said the State Department Deputy Spokesperson, Marie Harf.
There was no voting in the roughly 60 per cent of the country outside the control of Assad’s government.
Assad is all but certain to win a third, seven-year term despite two other nominal candidates.