Calls to set up a no-fly zone in Ukraine must be treated realistically, Luxembourg’s Foreign Minister Jean Asselborn said, warning against the risk of escalating the conflict. “Who would enforce it?” Asselborn said at a special NATO foreign ministers meeting on Friday to discuss the conflict. Asselborn warned it would be a world catastrophe for NATO to intervene in Russia’s invasion of Ukraine. “I think we need to keep our feet on the ground now,” he said. Foreign Minister of Spain José Manuel Albares said NATO foreign ministers would discuss the issue in the meeting.