"I will take up the matter with state leaders and indicate Finland's readiness to facilitate the start of a new round of negotiations," he was quoted as saying by Yle, a Finnish public broadcaster.
Speaking at a national defense meeting in Helsinki, Niinisto warned that dissolving treaties posted huge risks to international security.
"Having an arena without treaties would present enormous risks. The Cold War of our past would be surpassed by an Ice Cold War," he stressed.
Niinisto spoke the same day as the United States reimposed sanctions on Iran after quitting a historic 2015 nuclear agreement, which curbed Tehran’s atomic energy program.
Last month, the United States threatened to abandon a Cold War era pact with Russia, the Intermediate-Range Nuclear Forces Treaty (INF), which bans both countries from building medium-range ground-based nuclear missiles.