Next, Germany annexed Austria in March 1938. A few days after this Poland delivered an ultimatum, demanding that Lithuania sign a peace treaty with Poland. Without support from their Baltic neighbours, the Lithuanians had to accede to the ultimatum. In September, the Germans occupied Czechoslovakia. Next, the Germans aimed to regain the Polish Corridor and Klaipėda in Lithuania. On 20 March 1939, the Germans demanded Klaipėda from Lithuania. Two days later the Lithuanians agreed, losing 30 percent of their industrial capacity and their only major sea port. The dismemberment of Czechoslovakia caused France and Great Britain to guarantee Polish integrity on 30 March.