Member of the Finns Party Mika Niikko had to leave his position as chair of the Foreign Affairs Committee after he suggested that French President Emmanuel Macron, or someone else, should publicly declare that Ukraine would never join NATO.
He later deleted the tweet and apologised, saying he had not thought the statement through before publishing it.
"The goal was not to take a position on whether Ukraine could seek Nato membership", Niikko said. "Ukraine is fully entitled to make its own decisions".
The Finns Party MP faced severe criticism for his original tweet.
"Finland's position is clear and has been restated regularly", said Centre MP Joonas Könttä. "All independent states have the right to decide on their own security. It is not Finland's place to advise on how other states should make those decisions".
Tensions over Ukraine have been escalating over the past months, with the US, Britain, and their allies accusing Russian of planning to invade the country. Moscow has repeatedly slammed the allegations, denouncing the "invasion" narrative as fake. At the same time, Russia has attempted to de-escalate the situation, coming forward with security proposals that suggest the bloc not expand to the east. However, the alliance has refused to abandon its "open-door" policy.
Kiev previously announced its intention to join NATO -- despite the fact that Ukraine is plagued by a civil war in Donbass, and a territorial dispute with Moscow since the unification of Crimea with Russia in 2014.