The Ryti–Ribbentrop letter of agreement () was a personal letter from President of Finland Risto Ryti to German Führer Adolf Hitler signed on 26 June 1944. It was sent during the Soviet Vyborg–Petrozavodsk Offensive, which had started on 9 June and threatened to knock Finland out of the Continuation War. The letter was a product of a week of Finno-German negotiations, where the Germans sought a political commitment to the war, while the Finns sought increased military aid in the form of both troops and materiel. In the letter, Ryti agreed not to seek a separate peace in the war with the Soviet Union without approval from Nazi Germany. The letter was intentionally phrased by the Finns in a way where it would not bind Ryti's successors, as Finland had already contacted the Soviet Union in secret, seeking to exit the war. During the negotiations, the Germans sent to Finland one infantry division, a brigade of assault guns, and a Luftwaffe detachment. The Finns also received significant amounts of anti-tank weaponry. Because most of the German aid either predated the agreement, or alternatively arrived too late to meaningfully contribute to the Finnish success in stabilizing the military situation, historians have questioned whether the agreement was a necessity for the Finns. The agreement, which completely bypassed the Finnish Parliament, was criticized heavily both within Finland and internationally. In July, Germany pulled all forces out of southern Finland, and Ryti resigned on 1 August, resulting in a Finno-Soviet armistice on 2 September. As a condition for peace, Finland had to remove any remaining German forces from Lapland, resulting in the Lapland War. Historical background The Finnish military ties to Germany date back to World War I and the Finnish Civil War. During World War I, some 1,900 Finnish volunteers of the Jäger Movement traveled in secret to Germany where they received military training and formed the 27th Royal Prussian Jäger Battalion. The Battalion fought as part of the Imperial German Army on the Eastern Front of World War I. Following the start of the Finnish Civil War on 27 January 1918, the volunteers returned to Finland to fight on the side of the Whites. They took various roles in the White army, with some 400 jägers being promoted to officers and approximately 660 becoming non-commissioned officers. The jägers were soon joined by Imperial German forces who also took part on the side