Sergei Kuralenko, head of Russia's coordination center in Syria, announced on Sunday that a series of local ceasefires across the embattled country were "observed."

"The positive results reached have allowed us in coordination with Syria's authorities and American partners to extend the silence regime in Eastern Ghouta for one more day until midnight on May 1," Kuralenko said, according to Russia's state-owned TASS news agency.

The military official added talks were underway to establish a ceasefire in Aleppo, where fighting between government forces and rebels have left scores of civilians dead over the past week.

The US State Department on Saturday said State Secretary John Kerry head to Geneva, where he is expected to meet with UN special envoy for Syria Staffan de Mistura along with the foreign ministers of Saudi Arabia and Jordan.

Kerry "will review ongoing efforts to reaffirm the cessation of hostilities nationwide in Syria, obtain the full humanitarian access to which the Syrian government committed and support a political transition," the state department said in a statement.

A new ceasefire?

The US and Russia brokered a "cessation of hostilities" that went into effect on February 27. However, it has largely fallen apart after the Saudi-backed mainstream opposition alliance High Negotiations Committee (HNC) suspended its participation in peace talks citing ceasefire violations and blocked aid deliveries.

"It is not suitable, neither morally nor on the humanitarian side, to be part of negotiations when Syrians are dying daily from sieges, hunger, bombings, poisonous gases and barrel bombs," HNC leader Riad Hijab said.

Over 200 civilians have been killed since violence erupted in Aleppo on April 22, according to the UK-based Syrian Observatory for Human Rights (SOHR), which relies on a series of on-the-ground informants in Syria.

'Only game in town'

Robert Colville, spokesman for the Office of the UN High Commissioner for Human Rights (UNHCR), said on Friday that more needed to be done to ensure the "cessation of hostilities" alongside peace talks.

"It's really the only game in town; the cessation of hostilities and the Geneva talks are all that there is. And as we know that they've stopped at least for the time being it looks like the fighting is about to get back into full swing and the prospects of that are truly horrendous," Colville said.

More than 270,000 people have been killed and roughly half the population displaced since the conflict erupted in 2011, when government forces cracked down on pro-democracy protesters calling for President Bashar al-Assad to resign.