Italy's foreign minister urged European leaders on Thursday to tackle the continent's migration crisis and avert a potential collapse of the free-travel Schengen zone, hours before they meet on the issue in Brussels. "We anticipate that, albeit belatedly, Europe will multiply its commitments" to resolve the migration crisis, Italian Foreign Minister Paolo Gentiloni during a visit to Athens. "Unilateral actions that will lead to the collapse of the Schengen treaty must be avoided," he said in comments translated into Greek, urging countries to avoid actions that could have an "irreversible impact" on the European Union and Schengen.