Yesterday in Washington the US President deputy councilor on national security Steven Hedli and Armenian defense minister, secretary of the Council for security Serge Sarkisian discussed the issues on Armenian-American cooperation in military sphere as well as the situation in South Caucasus. As RA MFA press service reports, on the same day the official delegation headed by the Armenian defense minister visited the US National institute of defense. Today the high-rank military delegation of Armenia will return to Yerevan.