More than 3 million people have fled Ukraine since Russia launched its invasion, according to new estimates.
A United Nations agency said the milestone had been reached nearly three weeks into the war, which has killed hundreds of civilians, separated families and devastated cities.
It comes after 1 million refugees were estimated to have fled the country in the first seven days.
The figure surpassed 3 million on Tuesday, according to the International Organisation for Migration (IOM), who warned millions more could be affected if the war being waged in eastern Europe continues.
UN officials have called it the largest refugee crisis in the continent since the Second World War.
Out of the 3 million refugees to have fled into neighbouring countries, more than 157,000 of these are not Ukrainian citizens, according to IOM estimates.
Paul Dillion, a spokesperson for the group, said the new figures came from data from national authorities.
The UN Refugee Agency (UNHCR), which provides a more detailed count than the IOM though based on similar data, said more than 1.8 million of the refugees from Ukraine were now in Poland, while hundreds of thousands have gone to Western Europe.
According to the UNHCR, those fleeing early in the conflict mostly had resources and contacts outside Ukraine, but now many of the refugees are leaving in a hurry and more vulnerable.
“We see a lot of elderly people and a lot of persons with disabilities, really people who were expecting and hoping until the last moment that the situation would change,” Tatiana Chabac, a UNHCR aid worker, said.
Matthew Saltmarsh, a UNHCR spokesman, said most of those who have fled the Russian invasion - which started on 24 February - have been women and children.
Men of military age have been prevented from leaving the country.
Others have struggled to leave cities under attack, such as Mariupol where the first successful evacuation convoy took place this week after numerous failed attempts.
The Independent has a proud history of campaigning for the rights of the most vulnerable, and we first ran our Refugees Welcome campaign during the war in Syria in 2015. Now, as we renew our campaign and launch this petition in the wake of the unfolding Ukrainian crisis, we are calling on the government to go further and faster to ensure help is delivered. To find out more about our Refugees Welcome campaign, click here. To sign the petition click here. If you would like to donate then please click here for our GoFundMe page.
