Kalchev served as officer first into Bulgarian annexed territories, but later was sent into the German occupied Thessaloniki to found there a Bulgarian military club, when the German High Command approved it in 1941. The Bulgarians soon organized supplying of food and provisions for the Bulgarian population in Central and Western Macedonia in an attempt to gain support. Many Bulgarian political prisoners were released with the intercession of Bulgarian Club in Thessaloniki, which had made representations to the German occupation authorities.