The below is attributable to Spokesperson Heather Nauert:
U.S. Secretary of State Mike Pompeo spoke by phone today with Edgars Rinkevics, Minister of Foreign Affairs of the Republic of Latvia. Secretary Pompeo congratulated Latvia on celebrating 100 years of independence in 2018 and reiterated the United States’ commitment to collective defense under Article 5 of the North Atlantic Treaty and to the security of Latvia. Secretary Pompeo and Minister Rinkevics also discussed global, regional, and bilateral issues of mutual concern.
Source: U.S. Department of State