Yacoub El Hillo, the UN resident coordinator in Damascus, said the United Nations was ready with supplies and help for 1.7 million people in Syria's less accessible areas as soon as the parties to the civil war gave their approval.

"It is the best opportunity that the Syrian people have had over the last five years for lasting peace and stability," El Hillo said in a statement Sunday.

He warned against celebrating too soon, however, saying that "we all know that without a meaningful political process and a political solution, both cessation of hostilities and entry of humanitarian assistance will not be enough to end the crisis in Syria."

The UN hoped to reach the first of the besieged towns, Moadamiya, on Monday.

Accusations test truce

At the same time, key actors in the civil war were busy trading blame over violations of the ceasefire since it went into effect on Saturday. Brokered by the United States and Russia, the truce only applies to the government of President Bashar al-Assad and an umbrella group of moderate rebels and does not include "Islamic State" or al Nusra Front.

Though it described the cessation of hostilities as "positive," Syria's primary opposition group, the High Negotiations Committee (HNC), has also complained to the United Nations that the governmen and its allies had committed "24 violations with artillery shelling and five ground operations ... in 26 areas held by the moderate opposition."

HNC head Riad Hijab said the violations had killed 29 people and injured dozens of others.

Meanwhile, officials from Russia, which has long backed Assad, said they had registered nine breaches of the truce by Sunday.

Undeterred by the violations, Russian Foreign Minister Sergey Lavrov and his US counterpart, John Kerry, held talks about the truce late Sunday. According to Reuters news agency, the Kremlin said they had discussed closer military cooperation in Syria to boost its validity.

"We have violations here and there, but in general it is a lot better than before and people are comfortable," the HNC announced, adding to hopes that the peace deal could lead to a more lasting agreement to bring about an end to the five-year conflict that has killed hundreds of thousands of people and displaced millions.

es/kms (AFP, dpa, Reuters)