The proximity of the Finnish border – from downtown Leningrad – and the threat of a Finnish attack complicated the defence of the city. At one point, the defending Front Commander, Popov, could not release reserves opposing the Finnish forces to be deployed against the Wehrmacht because they were needed to bolster the 23rd Army's defences on the Karelian Isthmus. Mannerheim terminated the offensive on 31 August 1941, when the army had reached the 1939 border. Popov felt relieved, and redeployed two divisions to the German sector on 5 September.