UN humanitarian chief Valerie Amos has urged the Security Council to act immediately to ensure more humanitarian access in war-torn Syria, according to BBC News.

Calling for a resolution, she said it was "unacceptable" that both Damascus and rebels continued to "flagrantly" violate humanitarian law.

The council has been deadlocked over aid deliveries in Syria, where millions have been forced to flee their homes.

Briefing the UN Security Council on Thursday, Feb 13, Baroness Amos said: "It is unacceptable that four months since the members of that Council demanded action, international humanitarian law continues to be consistently and flagrantly violated by all parties to the conflict. All parties are failing in their responsibility to protect civilians. We understand that a war is going on, but even wars have rules."

Speaking to the BBC, Baroness Amos said a UN-brokered ceasefire deal which has allowed civilians to be evacuated from the besieged Old City of Homs in the past few days did not offer a long-term solution.

"It's 14 months since I raised the alarm in the Security Council about Homs. We managed to get 1,200 people out of Homs, we managed to get food and medicines in for 2,500 people," she said. "If it's going to take 14 months to do that when you've got 250,000 people in besieged communities, when you've got over three million people in hard-to-reach communities, I really find it very difficult to say that this is a [right] model."

The Security Council remains deadlocked over the issue.

The U.S., Britain and France favor a toughly-worded resolution, but it is opposed by Russia which has put forward an alternative draft on fighting what it calls "terrorism" in Syria and offering its own plan for improving aid, our correspondent adds.

The civil conflict in Syria has claimed more than 100,000 lives since March 2011. Some 9.5 million people have been forced to flee their homes.