Syrian Kurdish refugees from the Kobane area sit by a fire at a camp in Suruc on the Turkey-Syria border Nov. 13. A U.N. official said on Nov. 17 that the flood of Syrian refugees could harm neighboring nations. (Vadim Ghirda/AP)

The crises in Syria and Iraq have caused a flood of refugees that could destabilize neighboring countries and pose a threat to countries around the world, the senior refu­gee official for the United Nations said Monday.

More than 13 million people, roughly the equivalent of Istanbul or greater metropolitan London, have been displaced by the conflict in the two countries, said António Guterres, the U.N. High Commissioner for Refugees.

The “mega-crisis” has caused so many Syrians and Iraqis to flee their homes that last year the number of refugees worldwide topped 50 million, the greatest number since World War II. At least 32,000 people became refugees every day last year, Guterres said, more than double the pace as recently as three years ago, and the speed has accelerated this year.

The wave of refugees from Iraq and Syria has already overwhelmed neighboring countries like Turkey, Jordan and Lebanon. Guterres cited strains in a Lebanese village he visited recently where 5,000 Syrian refugees outnumbered the 3,000 Lebanese residents, competing for scarce jobs and resources.

“It’s been a dramatic threat to regional stability, even a global threat,” Guterres said of the conflict in Syria and Iraq. “It’s attracted fighters from all over the world who are going to go home one day and represent a clear danger to their own countries.”

Guterres is in Washington to draw attention to a U.N. campaign to end statelessness among people who are born as refugees and never gain citizenship and the rights that accompany it. During an interview at the UNHCR offices in downtown Washington, Guterres talked about the staggering refu­gee crisis that is expected to grow even worse in coming weeks as winter approaches.

The UNHCR faces a $58 million shortfall in funding to buy tents, blankets, fuel and food just for people who are displaced within Syria and Iraq. The agency is considering setting priorities for who gets help — families with children, headed by women or with health issues, for example. As many as 1 million people may be turned away, the agency estimates.

The United States has donated $1.3 billion to the UNHCR this year, more than any other nation. It also has accepted 75,000 refugees from around the world. Other big donors include the European Union, particularly member countries Germany and Sweden, and the Persian Gulf countries of Kuwait and Saudi Arabia.

Guterres said he expects the number of new refugees to continue growing at a rapid pace. Their ranks are driven not only by warfare, but also by environmental factors such as population growth, climate change and water scarcity.

Stable countries need to do more than fund humanitarian aid and accept refugees for resettlement, he said. He called for more policies that help stabilize countries that are not in crisis but are stretched beyond their limits by the destabilization of their neighbors.