UN Undersecretary-General for Humanitarian Affairs Martin Griffiths on Monday called for the protection of humanitarian workers in Ukraine and for more resources.

"Right now, we urgently need progress on two fronts if we want to reach more people with aid that they need, that they deserve," he told a Security Council meeting on the humanitarian situation in Ukraine.

"First, we need assurances from parties to the conflict that humanitarian workers and movements will be protected even during the most severe days of the conflict and not waiting for the conflict to subside," he said. "Even now, even today, we need to provide those protections to those workers to do the job that they want to do."

Under international humanitarian law, all parties must allow and facilitate rapid and unimpeded passage of impartial humanitarian relief for civilians in need and must ensure the freedom of movement of humanitarians, he said.

"And secondly, of course, we desperately need more resources," said Griffiths.

On Tuesday, UN Secretary-General Antonio Guterres will launch a humanitarian appeal for the Ukraine situation with two components: a three-month flash appeal for the situation inside the country, and a regional refugee response plan for the situation outside, he said.

He called on member states to show support with quick, generous and flexible funding.

The most pressing humanitarian needs are for emergency medical services, including sexual and reproductive health services, critical medicine, health supplies and equipment, safe water for drinking and hygiene, shelter and protection for the displaced, said Griffiths.

He said every effort must be made to de-escalate the conflict.