A young Ukrainian mother carries her three-month-old baby and her three-year-old toddler across the border into Hungary after she fled Ukraine leaving her husband behind. © UNHCR/Zsolt Balla

Every day, the plight of civilians in Ukraine grows more desperate. As the war continues to escalate, I’m being inundated with messages from people asking what they can do to help Ukrainians in their darkest hour.

Support is badly needed. The Russian invasion is just weeks old, yet the human cost is already devastating. Indiscriminate attacks on homes, schools, infrastructure, and health facilities have killed hundreds, left people without food, water and medicine and plunged whole districts into darkness.

UN Secretary General António Guterres is calling for an immediate ceasefire and withdrawal of all Russian troops from Ukrainian territory. Intensifying fighting, in which innocent children are killed as they try to flee, must stop, right now. Civilians and humanitarians urgently need safe passage.

The world is watching in abject horror. Relatives and friends have been emailing for days asking what they can do. Many are offering to help refugees, donate cash and supplies, or even put someone up in a spare room. The response has been overwhelming and endlessly heart-warming.

Ordinary people have shown heart and ingenuity. Volunteers are welcoming refugees at the Polish border, or in Berlin. In my own circle, a colleague’s home town in Italy has sent busses laden with food, clothes, toys and medicine to Ukraine’s borders to collect refugees and bring them back to a warm community refuge. My daughter’s friend found housing for a family of seven who showed up at the train station with no place to go. Such displays of warmth are priceless to those forced to flee.

Millions more are donating supplies or fundraising in their local communities. One grassroots initiative has seen people booking Airbnb apartments in Ukraine as a way of showing solidarity and donating lost income. These gestures offer hope and boost the resilience of those seeking safety.

Every offer of help is vital. There is a staggering exodus underway. UNHCR, the UN Refugee Agency, says more than 2 million people have fled the country in less than a fortnight, numbers not seen in Europe since World War II. Most of them are women, children, and elderly people.

Hundreds of thousands more are on the move inside Ukraine, taking dangerous routes westwards — in places under fire — to escape the shelling. Roads are unsafe, food and medicine scarce, cash reserves are dwindling. A humanitarian catastrophe is looming.

In the already war-torn east, the outlook is even worse. There, in Donetsk and Luhansk, eight years of conflict had already devastated communities, costing 7,000 lives and leaving 3 million people relying on humanitarian assistance from the United Nations and partners.

The UN is urgently scaling up its humanitarian response in and around Ukraine. To do so it has launched two coordinated emergency appeals calling for a total of US $1.7 billion to help Ukrainians over the coming months with shelter, healthcare, food, and other essentials.

Moderating a live pledging session on March 1, I was greatly heartened by the response. A massive $1.5 billion was promised to the humanitarian relief efforts, including the inter-agency appeals. This is among the fastest and most generous responses a UN flash appeal has ever received.

Of that, $1.1 billion will go to helping 6 million people inside Ukraine get through the next three months. The money will help provide food, medicine, safe drinking water, shelters, repairs for damaged homes, emergency cash assistance and winter relief. Governments donated generously, but the outpouring of giving from people all over the world has been so inspiring. Here are ways you can donate too.

Funds will also go to help those who have fled Ukraine, focusing on the most vulnerable — lone children, the disabled, the elderly, and mothers with kids. Our inter-agency Regional Refugee Response Plan will support neighboring countries provide shelter, healthcare, local transport, and other essentials.

The UN has stockpiles of aid inside Ukraine and is shipping more life-saving items to its borders. But it’s also crucial those affected can buy what they need for themselves. One of the most effective ways to help is for us to provide refugees and internally displaced people directly with cash via cards.

We must hope for the best and prepare for the worst. We face what could become Europe’s worst humanitarian and refugee crisis in decades. Those fleeing violence need open borders, safe places to stay, and the means to take care of themselves. This crisis is unlikely to be over quickly.

Tragically, the longer the war goes on, the wearier the world will get. We know that attention spans are not infinite. Yet the UN is committed to stay and deliver in and around Ukraine, always. We need your help to do so. If you can, donate to our humanitarian crisis appeal.