Dekanozov was responsible for purges of the Red Army as well as for purging Nikolai Yezhov's supporters from the NKVD. In May 1939 he was appointed deputy chief of the People's Commissariat for Foreign Affairs (NKID). His sphere of responsibility before 1941 included Iran, Turkey, Afghanistan, Mongolia, and Xinjiang, as well as the consulates, cadres, and finances of NKID. Soviet military forces crossed the Lithuanian border on 15 June 1940, with the military of Lithuania being ordered not to resist. Dekanozov arrived on the same day to organise the incorporation of Lithuania into the Soviet Union. The Communist Party of Lithuania, headed by Antanas Sniečkus, was at his disposal. The Soviet military established a controlling presence that allowed Dekanozov to fulfill his function as representative of the Communist Party. The process creating the Lithuanian Soviet Socialist Republic was Dekanozov's work. He installed himself in the Soviet embassy and imposed on Lithuania the Soviet party-state structure in which the traditional governmental forms were of only secondary importance. Dekanozov restructured the Lithuanian government, naming Justas Paleckis, a Lithuanian leftist who was not yet a member of the Communist Party, as Prime Minister. Aided by specialists for Soviet administration and Soviet security organs sent in from Moscow, Dekanozov worked through the Lithuanian Communist Party, while the cabinet of ministers, headed by Paleckis, served an administrative function. Dekanozov and Paleckis brought a number of non-members of the Communist Party (but still pro-communists) into the first "people’s government", but in retrospect it is clear that they constituted window dressing for the Soviet takeover. For his part, Dekanozov pushed his program carefully, concentrating first of all on denouncing the Smetona regime in Lithuania, then promising to respect private property, assuring Lithuanians that agriculture would not be collectivized, and restraining any discussion of the possibility of joining the Soviet Union until mid-July. On 6 July Dekanozov’s government announced that on 14 July there would be elections for a new parliament, a so-called People's Seimas. The Lithuanian Communist Party announced the formation of the Union of the Toiling People of Lithuania, which offered a slate of candidates, including some ten non-members of the Communist Party, with as many people as there were seats in the new parliament up for election.