The United States and Russia have said that a cessation of hostilities in Syria is largely holding and it should be extended by 48 hours, as the United Nations urged all sides to guarantee the security of an aid convoy, currently held-up along the Turkish border, into Aleppo.

"There was agreement as a whole, despite sporadic reports of violence, the arrangement is holding and violence is significantly lower," State Department spokesman Mark Toner said at a press briefing on Wednesday.

"As part of the conversation they agreed to extend the cessation for another 48 hours."

Toner said US Secretary of State John Kerry and his Russian counterpart Sergey Lavrov had spoken by telephone earlier in the day and agreed it was worth extending the truce. 

Under the deal, which was brokered by the US and Russia on Friday, Washington and Moscow are aiming for reduced violence over seven consecutive days, before they move to the next stage of coordinating military strikes against ISIL and Jabhat Fateh al-Sham, the group formerly known as al-Nusra Front that changed its name after cutting ties with al-Qaeda in July.

Syria ceasefire comes into effect under US-Russia deal

The UK-based Syrian Observatory for Human Rights, which monitors the Syrian conflict through contacts on the ground, said no deaths from fighting had been reported in the first 48 hours of the truce.

"This recommitment will initially be for 48 hours, and, provided it holds, the US and Russia will discuss extensions, with the aim of achieving an indefinite extension to lower the violence," Toner said.

He added that Russia needed to use its influence over Syrian President Bashar al-Assad to ensure that humanitarian aid was delivered to besieged communities under the agreement.

"We haven't seen the humanitarian access yet so we're still continuing to assess this, talking to the Russians," Toner he said. "We're pressuring them to pressure the Assad regime."

Stalled aid deliveries 

The extension of the ceasefire, which began at sundown on Monday, comes as aid convoys meant to reach besieged populations in the northern city of Aleppo remain stalled along the Turkish border. 

Twenty lorries loaded with much-needed food and other aid destined for rebel-held neighbourhoods of Aleppo, home to some 300,000 people, remained at the border on Wednesday awaiting the all-clear for the journey into the embattled city. 

"I've urged the Russian government to make sure that they exercise influence on the Syrian government, and also the American side to make sure that Syrian armed groups, they also fully cooperate," UN Secretary-General Ban Ki-moon told a news conference on Wednesday. 

The convoy of aid was supposed to head towards Aleppo on Wednesday, but Ban said the security arrangements were still not in place.

"They are at the border with Syria. They are still there," Ban said.

The UN estimates that well over half a million people are living under siege in Syria, where a five-year conflict has killed hundreds of thousands and displaced more than 11 million.

People gather near burning tyres during a demonstration against forces loyal to Assad [Reuters]

On Wednesday, both Moscow and Washington spoke positively about the truce deal, with the Kremlin saying it raised hopes for a peaceful solution to the crisis.

Kerry also said it was a "last chance" to keep Syria together, with Washington hoping it will revive peace talks aimed at ending the conflict.

However, prominent Syrian opposition politician George Sabra said the many violations of a previous truce had undermined confidence in the current ceasefire, adding that it was too early to talk about a resumption of peace talks that were abandoned in April.

Tense ceasefire largely holding across Syria

Speaking to Reuters, he lamented a lack of mechanisms to enforce the ceasefire and accused the Assad government and its allies of committing minor violations "to impede the other goals of the truce, such as delivering necessary aid to besieged areas".

David Swanson, spokesman for the UN Office for the Coordination of Humanitarian Affairs, said disagreements between the warring sides were blocking aid getting into opposition-held eastern Aleppo.

"Some groups are looking to gain political mileage out of this, and this is something we need to put aside," he told Reuters.

A second UN official said that deliveries to Aleppo had to cross numerous checkpoints operated by both opposition and government forces, and it was still unclear whether the aid could get through safely.

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But the opposition's Sabra blamed Damascus, saying the government's insistence on controlling aid was obstructing its delivery to Aleppo under the agreement.

The Syrian government has said it will reject any aid deliveries to the city not coordinated through itself and the UN, particularly from Turkey, which has backed the rebels fighting Assad.

A diplomatic source, speaking to Al Jazeera on condition of anonymity on Wednesday, confirmed that the Turkish government's involvement remains a major sticking point.

"Politics is coming in the way of the delivery," the source said.

The UN says it must get permission for most of its aid deliveries from Damascus. The global body has repeatedly criticised the Syrian government for restricting access, especially to besieged areas, and for removing vital items from convoys. 

Source: Al Jazeera News And Agencies