Reference

The Finnish President who suggested that the state acquire Tamminiemi as the President's residence was Kyösti Kallio. This information is supported by a Wikipedia article on Tamminiemi, which states that President Kallio, who had befriended the owner of Tamminiemi, suggested that it be donated to the "poor state" to serve as the President's residence [1]. Urho Kekkonen, who became president in 1956, was one of the most notable residents of Tamminiemi, and it remained an official residence until a new residence was built for President Koivisto in 1983 [2]. For more detailed historical context, the official website of the Finnish Presidency and the Urho Kekkonen Museum Tamminiemi provide additional insights into the use and significance of Tamminiemi as a presidential residence [3][4].

Sources: [1] https://en.wikipedia.org/wiki/Tamminiemi [2] https://www.kansallismuseo.fi/en/tamminiemi/tamminiemen-historiaa [3] https://www.presidentti.fi/en/presidency/official-residences/mantyniemi/ [4] https://www.tripadvisor.co.uk/Attraction_Review-g189934-d245536-Reviews-Urho_Kekkonen_Museum_Tamminiemi-Helsinki_Uusimaa.html