In 1953, Levitan accepted an invitation from Mossad director Isser Harel to establish contacts in the Soviet Jewish Community. This was part of an effort by a small, new clandestine agency that reported to the Prime Minister's Office. Originally known as "Bilu," it was known by the code name "Nativ" and was officially called Lishkat HaKesher, or the "Liaison Bureau." Levitan changed his name to the more Hebraic-sounding Nehemiah Levanon, as many Israelis did at the time. At the time of his posting, the Soviet Union had broken off diplomatic relations (in response to the 1953 bombing of the Soviet embassy in Tel Aviv). Levanon therefore worked in Sweden until ties were re-established later that year.