(CNN)In the parking lot of a refugee reception center just inside Poland, Ukrainian women spoke last week with a bus driver as aid worker Chris Skopec stood nearby.
"It looks like I'm going to Germany," one of the war refugees told Skopec as she laughed hysterically. "How ridiculous is that?"
Then, the next moment, the woman was weeping, Skopec recalled. Her husband and two sons were still far inside Ukraine, where humanitarian needs were burgeoning amid Russia's bombardment. Here she was, at the first meager waypoint on her migrant journey. And if she took this ride, she'd be headed into the unknown, unsure where she'd even sleep.
"And she got on the bus," Skopec, executive vice president of global health for Project HOPE, told CNN. "That's everyone's story."
More than 3 million people have fled Ukraine since the invasion began more than three weeks ago, according to the International Organization for Migration, or IOM, and legions more flee to the border every day. Meantime, many more of Ukraine's 45 million residents remain in a country where active conflict has cut off access to basic supplies like medicine.
To serve their needs, the United Nations and its partners on March 1 launched an emergency appeal for $1.7 billion. Of that, $1.1 billion would go toward helping 6 million people inside Ukraine over the next three months and nearly $551 million help support Ukrainians who fled to other countries in the region.
Aid groups are working now to address the massive humanitarian crisis -- inside Ukraine, along the country's borders and in places of refuge far beyond. At each stage, Ukrainians face distinct needs, aid officials have found, and delivering proper resources at each one is no easy task.
Inside Ukraine, everything is needed
The need for medical supplies inside Ukraine is so great that Skopec stopped compiling lists. Every hospital is saying the same thing, he told CNN: "We're running out of everything."
He and a Project HOPE team traveled last weekend into Ukraine to deliver a shipment of medical supplies to a 4,000 bed, three-hospital network in Lviv. Among the supplies were specialized sutures used in a heart transplant the very next day, he said.
"Of course, we can talk a lot about the life we saved there, but this is a country of 45 million," he said. "So, we won't and can't stop with the idea of just helping one person."
Resupplying health care facilities -- and the doctors, nurses and support staff now doing their jobs in a war zone -- is the principal focus of Project HOPE's efforts inside Ukraine, said Skopec. The 64-year-old organization's mission is supporting health care workers around the world.
But as the demand for health care services inside Ukraine is greater than ever, the nation's supply chain has been severely disrupted, Skopec told CNN. He compared the needs to those of American doctors and nurses at the beginning of the Covid-19 pandemic: In Ukraine, health care workers in clinical settings are running out of masks and trauma supplies.
Another aid group, Americares, has sent 3 tons of critical medicine and medical supplies to Ukraine, its vice president of emergency programs, Kate Dischino, said in an email. And it's working on getting more.
"We are getting requests from he