UNITED NATIONS, Feb. 26 (Xinhua) -- Staggering levels of humanitarian need persist throughout Syria and an estimated 11.7 million people will require humanitarian assistance across the country in 2019, said a UN official on Tuesday.

Reena Ghelani, director for operations and advocacy of the UN Office for the Coordination of Humanitarian affairs (OCHA) told the Security Council that an estimated 2.7 million men, women and children remain in need of humanitarian assistance across northwestern Syria. Some 40 percent of children are out of school, while 2 million residents rely on water trucking for most of their clean water.

"Ensuring sustained humanitarian access is therefore critical," she said, on behalf of the Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Mark Lowcock.

On the plight of civilians in Idlib and surrounding areas in northwest Syria, Ghelani said that they "simply have nowhere else to flee should there be a full-scale military incursion into the area."

While the September agreement between Turkey and Russia to establish a demilitarized zone staved off an immediate military escalation, the last few weeks witnessed an increase in fighting, with dozens of civilians reportedly killed and dozens injured, she added.

Up to 36,000 people are reported to have been displaced due to intensified shelling, many of them having moved northward and are now residing in camps on the border with Turkey, Ghelani said.

"I reiterate today that the risk of military escalation, and of potentially catastrophic humanitarian consequences, persists," said Ghelani, adding that it is critical to sustain and fully implement the Russia-Turkey agreement.