President Niinistö’s comments came as he visited Lappeenranta in southeast Finland with visiting Swedish royals, King Carl XVI Gustaf and Queen Silvia.
His remarks centred on recent political and public debate about property purchases by Russian nationals in border areas as well as other locations crucial to Finnish defence - so-called strategic areas.
Niinistö said that Finland might begin to map out protected areas near locations of strategic importance.
“One alternative would be a categorical ban. However I wouldn’t start there, but would look at special situations on a case-by-case basis,” he remarked.
The President said that he had discussed the matter last week with cabinet members and added that it would be further debated in greater detail in the coming weeks.
Earlier this week Defence Minister Carl Haglund said he'd like government to have the right to restrict real estate deals by foreigners near strategic sites.