Flouting demands for Syria ceasefires shows a "monstrous indifference" to the suffering of millions of children needing a respite from violence, a top UN rights official said Tuesday (March 13th).

A resolution adopted by the UN Security Council two weeks ago calling for a 30-day ceasefire across Syria has been broadly ignored, with attacks increasing on the opposition enclave of Eastern Ghouta.

Kate Gilmore, the UN Deputy High Commissioner for Human Rights, called for immediate action to help children caught in the fighting, AFP reported.

In an address to the UN Human Rights Council, she voiced particular concern for the some 125,000 children trapped in Eastern Ghouta, "many acutely malnourished, most profoundly traumatised".

"What is happening to those children is too graphic for our TV screens, but not graphic enough it seems to motivate those who can stop the senseless violence to do so," she said.

"Is it not tantamount to a monstrous indifference to the suffering of children that Security Council resolutions for ceasefires are flouted?" she asked.

Panos Moumtzis, the UN's top humanitarian official for Syria, said Tuesday that 2017 was "the deadliest year of the Syrian war for children".

"Sadly, 2018 started really in a terrible way as well," he told reporters, adding that in the first two months of the year, "more than 1,000 children were either reported killed or injured through the violence in multiple locations".

A full two-thirds of Syria's 8.4 million children need humanitarian assistance, while one million of them live in areas that are difficult to reach by aid convoys and 170,000 in besieged areas, according to UN figures.