The Red Cross on Tuesday said it is "deeply alarmed" by the rapidly deteriorating security and living conditions of hundreds of thousands of newly displaced civilians in Idlib, northwestern Syria.

Ruth Hetherington, a spokeswoman for the International Committee of the Red Cross (ICRC), said at a U.N. briefing that those displaced "are running out of options to find basic safety for themselves and their families."

Adding to the growing international concerns about the tragedy unfurling for civilians in northwestern Syria, she said: "This is the worst wave of displacement we've seen during the Syrian conflict."

"Amid the harsh winter conditions in Idlib, we see people trapped, isolated and running out of ways to cope. It's completely unacceptable," said Hetherington.

She said deteriorating access to medical care and essential supplies for civilians in Idlib creates life-threatening situations that have already led to preventable deaths.

"Reduced access to health care, poor living conditions and difficulties with moving locations are among the major humanitarian consequences of the Idlib hostilities," said Hetherington.

With the ongoing fighting and shifting of frontlines, access for humanitarian workers and volunteers is challenging and risky, the ICRC said.

Hetherington quoted Fabrizio Carboni, the ICRC's Geneva-based director for the Near and Middle East, as saying: "We urge the parties involved to allow civilians to move to safety, either within the areas they control or across the front lines."

"The daily reality of cold, wet and snowy weather is compounding the conditions that create serious harm," said Hetherington.

"If civilians must flee for safety reasons, all possible measures must be taken to ensure that members of the same family are not separated and that everyone is relocated under satisfactory conditions of shelter, hygiene, health, safety and nutrition," she said.

It has been months now since regime forces sped up attacks on Idlib, the last opposition stronghold in the war-torn country, targeting innocent civilians under the pretext of fighting terrorists. However, the regime is not alone in its attacks, which have been ongoing since April 2019. As its backer, Russia is often active on the ground aggravating the humanitarian crisis.

According to a U.N. statement on Tuesday, nearly 900,000 people have fled the region due to the regime offensive on Idlib. This marked the biggest movement of migrants in the nine-year conflict.