Western leaders to test Putin's 'goodwill gesture' in Aleppo

French, Russian and German leaders will meet in Berlin to discuss Syria on Wednesday ahead of a brief Russia-backed truce in Aleppo, amid mounting criticism about Moscow's backing of Damascus' brutal offensive.

The Syrian opposition and Western governments have dismissed the truce as a ruse.

The trio's meeting will be aimed at "giving the same message to Vladimir Putin on Syria: a durable ceasefire in Aleppo and humanitarian access so that the devastation of this city can end," an aide to Hollande said.

The talks will come a day after the Kremlin announced that Russian and Syrian air forces had stopped bombing Aleppo prior to an eight-hour "humanitarian pause" in the battered city Thursday. Moscow described the move as a "goodwill" gesture.

This announcement was welcomed by the United Nations and the European Union, who also said the ceasefire needed to be longer to allow aid delivery.

EU foreign ministers said earlier this week they would press ahead with extending sanctions against Syrian President Bashar al-Assad's regime, but stopped short of threatening measures against Russia.

Merkel, however, said that in light of the "disastrous situation" in Syria, "no option, including sanctions, can be taken off the table".

Last week, tensions between French President Francoise Hollande and Russian President Vladimir Putin were raised after Hollande described the bombardment of Aleppo as a "war crime". Putin later cancelled a trip to Paris in response.

Speaking at the Council of Europe last week, the French leader later moved to allay fears of a deeper rift between the two nations.

"I consider it is necessary to have dialogue with Russia, but it must be firm and frank otherwise it has no place and it is a charade.

"I'm ready to meet President Putin if we can make progress on peace," the French leader said.

The European Union said earlier this week that the Russian and Syrian "deliberate targeting of hospitals, medical personnel, schools and essential infrastructure" could amount to war crimes.

Despite the Russian ceasefire announcement, Washington has expressed its scepticism, alongside opposition activists on the ground in Syria.

"We tried a ceasefire three times this year... No result," Abdel Rahman al-Mawwas of the civil defence White Helmets rescuers told AFP.

According the UK-based Syrian Observatory for Human Rights, air strikes were still being conducted in the broader Aleppo region on Tuesday.

Over 250,000 people are under government siege in Aleppo - a city that was once Syria's thriving commercial hub.

Damascus' offensive against rebel-held eastern Aleppo has destroyed hospitals and other human infrastructure, causing some of the worst violence that the country's five-year war has seen.