About 440,000 Syrians are now trapped in areas besieged by fighting, more than double the total from last month, as the war reaches “breathtaking levels of savagery”, UN aid chief Valerie Amos said Thursday.

Amos told the UN Security Council that Islamic State (ISIS) fighters are laying siege to government-controlled neighborhoods in Deir Ezzor, northeast Syria, adding 228,000 people to the growing list of civilians in need of aid, reports AFP.

“They are unable to leave the city and only minimal supplies have been airlifted in by the government,” Amos told the 15-member council.

“This increases the total number of people besieged in Syria from 212,000 to an estimated 440,000.”

Amos voiced concern over a recent upsurge in infighting after Islamist fighters from the Nusra Front launched an offensive to take the government-held city of Idlib.

Hundreds of thousands more people could be displaced and civilians could become trapped in the city if the fighting escalates, Amos warned.

The humanitarian aid chief delivered her grim assessment as she prepares to leave her post in May, with the crisis in Syria becoming even more dire.

“The situation in Syria has dramatically worsened,” Amos said. “We are in the fifth year of a war in Syria characterized by breathtaking levels of savagery.”

More than 215,000 people have been killed in the fighting and around half of the country’s population has been displaced.

Amos appealed for urgent Security Council action to ensure aid deliveries reach those in need, even though a resolution adopted a year ago that demanded all sides allow humanitarian access has not been enforced.

“Time is running out. More people will die,” Amos said.

She also called on the divided council to show “greater determination” to push for a political solution to end the war.

Amos and UN Secretary General Ban Ki-moon are due to attend a pledging conference in Kuwait on Tuesday to raise billions of dollars in aid needed to sustain the international aid effort in Syria.

The Security Council issued a statement calling for generous pledges at the Kuwait conference and recalled that previous appeals for funding had failed to generate contributions.