NATO Meeting Acting Defense Secretary Dr. Mark T. Esper meets with NATO Secretary General Jens Stoltenberg at NATO headquarters in Brussels, June 26, 2019. SHARE: Download: Full Size (1.89 MB) Tags: nato, partnerships, Mark T. Esper, Acting Defense Secretary Credit: Lisa Ferdinando, DOD VIRIN: 190626-D-BN624-0285.JPG Photo Gallery