Speaking to AFP in Tehran at the start of a regional tour, UN High Commissioner for Refugees Filippo Grandi said European leaders needed to do more to coordinate migration policies and to combat negative stereotypes about refugees.
"Refugees... Don't bring danger to us, they flee from dangerous places," said Grandi, who took office in January.
National leaders need to better explain that immigration "in fact contributes to the development of societies," he said.
"It provides a negative example to countries further away."
More From This Section
Protracted conflicts -- in particular Syria's five-year civil war -- have prompted an unprecedented wave of migration to the continent, with a record 1.25 million Syrian, Iraqi, Afghan and other migrants entering Europe since January 2015.
The influx has sparked a backlash in some countries, including in Austria where the anti-immigration Freedom Party nearly won the presidency last month and in Hungary where authorities have sealed the border with Serbia with razor wire and made illegal border crossing a criminal offence punishable by jail.
It was, he said, "a missed opportunity" because "each country made decisions separately. Borders closed."
He called for "a more collective collegial system of managing refugee flows based on solidarity and burden-sharing between the states, as opposed to trying to do it by themselves with the result that only some countries receive a large number of refugees and others close the borders."
Grandi also called for greater efforts to help those displaced by conflict within their own countries.