During the summer and autumn of 1941 the Finnish Army was on the offensive, retaking the territories lost in the Winter War. The Finnish army also advanced further, especially in the direction of Lake Onega, (east from Lake Ladoga), closing the blockade of the city of Leningrad from the north, and occupying Eastern Karelia, which had never been a part of Finland before. This resulted with Stalin asking Roosevelt for help in restoring peaceful relations between Finland and the Soviet Union on 4 August 1941. Finland's refusal of the Soviet offer of territorial concessions in exchange for a peace treaty would later cause Great Britain to declare war on Finland on 6 December (The US maintained diplomatic relations with Finland until the summer of 1944). The German and Finnish troops in Northern Finland were less successful, failing to take the Russian port city of Murmansk during Operation Silver Fox.