The below is attributable to Deputy Spokesperson Robert Palladino:?
In Sofia on December 14, during a meeting with Foreign Minister Ekaterina Zakharieva, Deputy Secretary John Sullivan advocated for NATO-interoperable U.S. systems as Bulgaria seeks to modernize its armed forces. The Deputy Secretary also emphasized the importance of further developing U.S.-Bulgarian commercial ties, fostering stability and economic development of the Western Balkans, and developing ever-closer cooperation within NATO. He also highlighted the importance for Bulgaria of enhancing its energy security.
Source: US Department of State