The last negotiations with Finland had been initiated by the Soviet side as part of its collective security policy in April 1938, and aimed to reach an understanding and to secure a favorable Finnish position in case of a German attack on the Soviet Union through Finnish territory, but this had proven futile due to the Finnish reluctance to break its neutrality, and negotiations ended in April 1939, shortly before Litvinov's dismissal. On October 13, 1939 new negotiations started in Moscow, and the Soviet Union (represented by Stalin, Molotov, and Vladimir Potyomkin) presented Finland with proposals including a mutual assistance pact, the lease of the military base of Hanko, and the cession of a 70 km-deep area on the Karelian Isthmus located immediately to the north of the city of Leningrad to the Soviet Union, in exchange for border lands further to the north. Finland, however, refused to accept the offer, withdrew from negotiations on November 7, 1939, and continued preparations for a possible Soviet invasion.