BRUSSELS (AP) — The European Union warned on Monday of a looming humanitarian "catastrophe" with tens of thousands of people traveling through the Balkans to northern Europe as winter closes in. The EU's 28 member nations have pledged to provide experts and funds to help manage the emergency, and to share refugees among them. "The European Union must do everything to avoid a catastrophe as winter closes in," Luxembourg Foreign Minister Jean Asselborn said after chairing the latest in a long series of high-level talks on the challenge.