Magne Barth heads the International Committee of the Red Cross delegation in Syria.

We at the International Committee of the Red Cross (ICRC) are working across the front lines in Syria to help millions of needy people, despite escalating violence and worsening security conditions.

If allowed, we could do much more to reduce the suffering of civilians, but it is increasingly difficult for us to enter contested areas and assist Syrians, let alone to protect them.

Three ICRC staff members who were abducted Oct. 13 in Idlib, in northern Syria, are still being held by an armed group. This has forced us to restrict our movement in some areas. Repeated requests to Syrian authorities to enter Moadamiyeh and other towns under siege around Damascus have gone unanswered. Volunteers from our partners at the Syrian Arab Red Crescent (SARC) regularly come under attack while attempting to deliver food, blankets and other supplies or to evacuate the wounded. Recently, a SARC ambulance came under fire in the southern town of Daraa; in a separate attack, a SARC volunteer lost his legs.

For humanitarians, few things are more frustrating than knowing that people desperately need help but that you’re not able to do more — not because you lack the will or capacity but because you are prevented from safely doing so.

We can work only when government forces and the armed opposition accept the ICRC’s humanitarian role. If they refuse to allow us safe access, we cannot reach people in dire need. The Syrian government and other parties to the conflict must permit us to enter the many areas directly affected by fighting. They must then take concrete measures to ensure the safety of ICRC workers and the people we assist while respecting our right to bring help first to those in greatest need.

The ICRC faces challenges beyond security and access. As desperation and cynicism become the norms of this conflict, the ICRC is routinely accused of having a hidden agenda. Specifically, we have been accused of failing to help civilians in certain areas and of colluding with the Syrian authorities or with opposition groups. Such claims are not new for an apolitical organization with 150 years of experience in conflict zones. But they are unfounded and disturbing. Moreover, they threaten the security of our staff and hinder our ability to assist, particularly in Syria’s most disputed areas.

Today, the ICRC and the SARC can work in many parts of Syria, thanks to the understanding and support of Syrian authorities, armed groups and, most important, the Syrian people. We are independent and impartial. We seek to assist and protect all people affected by the conflict, regardless of their origin, religion or political affiliation.

This principled approach has made a tangible difference in the lives of millions of Syrians. Together with the SARC, the ICRC has carried out dozens of relief operations across the front lines. Working with local water boards, we are providing drinking water to millions of people.

But the death toll is rising. More people are going missing, families are being displaced and millions lack access to basic services. We urgently need to step up our protection work and deliveries of water, food and medicine, particularly in areas where fighting has cut off supplies. As winter approaches, the needs and suffering will grow.

The incidents, threats and false rumors we have faced, particularly in recent weeks, jeopardize all humanitarian relief efforts. Our SARC colleagues have already paid a heavy price: Thirty-one volunteers and workers have been killed while carrying out their humanitarian duties since the conflict began in 2011.

Despite these setbacks, SARC volunteers and ICRC staff continue their lifesaving work, often in areas of Syria that are off-limits to other humanitarian agencies.

Yet with so many Syrians struggling for survival and humanitarian needs growing daily, we reiterate our call to be allowed, urgently, to reach all those in desperate need. Humanitarian workers must be allowed to relieve the plight of ordinary Syrians. They are bearing the brunt of this conflict.