"The main needs include cash, medicines & health services," the International Organization for Migration said on Twitter, adding that half of the displaced are women.
The agency added they will continue to deliver humanitarian aid in Ukraine.
On Feb. 24, Russia launched a war against Ukraine, which has met international outrage, with the European Union, US, and UK, among others, implementing tough sanctions on Moscow.
At least 1,430 civilians have been killed in Ukraine and 2,097 injured, according to UN estimates, with the true figure feared to be far higher.
More than 4.21 million Ukrainians have also fled to other countries, according to the UN refugee agency.
