The United Nations said Friday that, of the more than 6.6 million Ukrainian refugees who have fled to neighbouring countries, 2.9 million have moved on to other European nations.
Refugees, the vast majority women and children, have poured across Ukraine's borders since the Russian invasion on February 24.
The figure from the UN refugee agency UNHCR gives a picture of how many have stayed in the first country they entered and how many have headed on elsewhere as the displacement crisis triggered by the war spreads across the continent.
"According to the latest data we have available... 2.9 million refugees have moved beyond countries neighbouring Ukraine," UNHCR spokeswoman Shabia Mantoo told a briefing in Geneva.
A UNHCR graphic showed the largest numbers of Ukrainian refugees in non-neighbouring countries were in Germany, the Czech Republic and Italy.
A total of 6,659,220 Ukrainians have fled the country since the invasion, the agency's figures show. Of those, more than 3.5 million have headed west into Poland.
Around 100,000 refugees per day were arriving at the Polish border in early March but the number has slowed to around 20,000 throughout May.
"Newly arrived refugees often come from areas heavily affected by the fighting, some having spent weeks hiding in bomb shelters and basements," UNHCR spokeswoman Olga Sarrado told the Geneva briefing via videolink from a refugee case enrolment centre in Warsaw.
"They often arrive in a state of distress and anxiety, having left family members behind, without a clear plan for where to go, and with less economic resources and connections than those who fled earlier."
- Back-and-forth crossings -
The first weeks of the war saw volunteers flocking to help either at the borders or in welcoming new arrivals into their homes.
Sarrado said strong support from the wider international community would be needed to maintain that generosity and strength of response.
"The needs are only increasing as the conflict" grinds on, she said.
"Support will need to be provided so they can stay in the country until they can go back and live with dignity."
More than 1.1 million people have registered with the Polish authorities and received a state identity number which allows them access to public services.
Some 94 percent of those registered are women and children.
Ukrainians have crossed into Poland more than 2.1 million times since February 28 -- though these are not necessarily permanent returns.
"We have also seen more 'pendular' movements, where people go back and forth across the border to Ukraine for various reasons, including visiting families, checking their properties or returning to their jobs," said Sarrado.
"However, Poland expects to continue receiving and hosting a considerable number of refugees, given the large internal displacement, massive destruction and the ongoing hostilities in Ukraine."
Before the invasion, Ukraine had a population of 37 million in the regions under government control, excluding Russia-annexed Crimea and the pro-Russian separatist-controlled regions in the east.
