DAMASCUS: The UN on Wednesday urged governments to unlock the funds it desperately needs to assist one million refugees who have fled Syria's war, which a charity said increasingly features child soldiers.

UN High Commissioner for Refugees Antonio Guterres issued the appeal and warned of the "enormous threat" to the region from the two-year conflict that has already killed at least 70,000 people.

"I appeal to parliaments, governments to approve extraordinary funds to support the Syrian victims and the countries that receive them," Guterres said in Jordan which hosts 450,000 refugees, almost half of the total.

"If that does not happen, with the normal UN aid budgets we will not be able to deliver," he said, while calling for world powers to press for a solution or else face the "catastrophic scenario" of the conflict spilling over borders.

The appeal came a day after Syria said its army was ready to fight "for years" and world powers said they were drawing up a list of regime officials with whom the opposition can hold peace talks.

The latest diplomatic manoeuvres also come head of the second anniversary of the March 15 2011 nationwide protests that triggered the conflict.

The demonstrations broke out after the arrest and torture of children accused of painting anti-regime graffiti in the southern city of Daraa, which became a flashpoint.

Two years on, a British charity reported that children are being increasingly recruited on the front line, with both sides to the conflict using boys as soldiers and even human shields.

"There is a growing pattern of armed groups on both sides of the conflict recruiting children under 18 as porters, guards, informers or fighters," said Save the Children.

"For many children and their families, this is seen as a source of pride. But some children are forcibly recruited into military activities, and in some cases children as young as eight have been used as human shields."

One in three children reported having been hit, kicked or shot at, said the report, citing research carried out among refugee children by Turkey's Bahcesehir University.

Girls were forced into early marriage, thousands of children faced malnutrition, and millions were forced from their homes to live in parks, barns and in some cases caves, it said.

The British charity also called for all parties to the conflict to allow access to conflict zones and for governments to deliver on pledges to fund a $1.5-billion (1.1-billion-euro) humanitarian appeal for Syria.

In a report on Tuesday, the UN children's agency also said children have been recruited as soldiers in the spiralling conflict that it says threatens an entire generation of Syrians.

UNICEF said nearly two million children in Syria under the age of 18 were in dire need of aid, about 800,000 under 14 were internally displaced and that more than 500,000 children have fled the violence as refugees.

Meanwhile, Syria's exiled opposition Muslim Brotherhood called for a week of action both in the strife-torn country and elsewhere to mark the two years since the outbreak of the uprising.

"We call on the heroic Syrian people to bring back to life all aspects of the uprising... inspired by the spirit of real national unity, speaking in one voice," the exiled opposition group said.

On the ground, regime warplanes raided the strife-torn district of Baba Amr in Homs after rebels infiltrated the area, and clashes raged near the tense border with Lebanon, said the Syrian Observatory for Human Rights.

Wednesday's violence came day after at least 110 people were killed across the country, said the Observatory, which relies on a network of sources on the ground for its reports.

The toll excluded a member of the European Union delegation killed on Tuesday in a rocket attack on a suburb of Damascus, EU foreign policy chief Catherine Ashton said, identifying him as Ahmad Shehadeh.