Stoltenberg Handshake NATO Secretary General Jens Stoltenberg welcomes Acting Defense Secretary Dr. Mark T. Esper to Brussels for the NATO defense ministers meeting, June 26, 2019. SHARE IMAGE: Download Image: Full Size (0.83 MB) Tags: NATO, partnerships, Acting Defense Secretary, esper Photo By: NATO VIRIN: 190626-O-ZZ999-001E.JPG Photo Gallery