BRUSSELS (AP) — Hundreds of representatives from governments, agencies and charity groups are gathering in Brussels for a "solidarity conference" to drum up support for millions of Venezuelans who have fled the political crisis and particularly neighboring countries that are taking them in.

Around 4.5 million people have fled and numbers could soon surpass the 5.6 million who have left conflict-ravaged Syria since 2011 if departures continue at the same rate.

Most Venezuelans have remained in Latin America or the Caribbean, weighing heavily on their economies.

Before the conference, starting Monday, the Venezuela envoy for the U.N.'s refugee agency and the International Organization for Migration, Eduardo Stein, said the weight of arrivals in host countries "has overburdened their institutional scaffolding" and that "their budgets are exhausted."