After four days of negotiations, the Estonians had no choice but to accept naval, air and army bases on two Estonian islands and at the port of Paldiski. Soviet troop numbers in Estonia were put at 25,000. The mutual assistance treaty was signed on 28 September and the Soviets made similar treaties with Latvia on 5 October and Lithuania on 10 October. The latter treaty transferred Vilnius district to Lithuania. Finland was invited to enter similar negotiations on 5 October. Unlike the Baltics, the Finnish-Soviet negotiations lasted weeks without result. The Soviets invaded Finland on 30 November. The Finns were able to resist the Soviets for over three months; the nation lost over ten percent of its land area, though it retained its sovereignty.