The territory, historically part of Moldavia, was one of the five districts of Dorohoi County. Following the Molotov–Ribbentrop Pact of August 23, 1939, the Soviet Union issued on June 26, 1940 an ultimatum to Romania that threatened the use of force. The Romanian government, responding to the Soviet ultimatum, agreed to withdraw from the territories to avoid a military conflict. A few days later, Bessarabia and Northern Bukovina were occupied by the Soviet Union, and the Hertza region was attached to the Ukrainian Soviet Socialist Republic. As it was not mentioned in the ultimatum, the annexation of the Hertza region was not consented to by Romania. The region (together with the rest of Bessarabia and Bukovina) was recaptured by Romania during 1941–1944 in the course of the Axis attack on the Soviet Union in World War II, until the Red Army captured it again in 1944. Soviet annexation of this territory was internationally recognized by the Paris Peace Treaties in 1947.