US Secretary of State Mike Pompeo arrives in Brussels on Tuesday, ahead of an upcoming NATO summit. While President Trump arrives later on Tuesday and will most likely pressure the US’ allies to step up their defense spending, Pompeo will meet leaders on the sidelines with the aim of ratcheting up pressure on Iran and reassuring allies about alternative oil supplies. Pompeo arrived in the Belgian capital from Abu Dhabi, where he met with Emirati leaders to discuss Iran. Other State Department officials have also just returned from talks with Saudi Arabian leaders, where they discussed “new ways of depriving the regime of revenues,” Reuters reports.