Finland's Prime Minister Sanna Marin said Russia's invasion of Ukraine had "changed everything".
ADVERTISEMENTFinland will make a decision on whether to apply for NATO membership in "weeks rather than months", its prime minister has said.
Sanna Marin, speaking on Wednesday, said she was keen to build a consensus to join the alliance within the Finnish parliament.
She emphasised there was no fixed timetable but that "everything had changed with Russia's invasion of Ukraine".
"I think it will happen quite fast," said Marin. "It will happen in weeks, not months."
"All the parliamentary groups and also the president will have the opportunity to make the decision in the upcoming weeks."
Marin was in Stockholm to meet with her Swedish counterpart Magdalena Andersson and discuss the issue of joining the transatlantic military alliance.
Until now, both Helsinki and Stockholm have shied away from joining NATO, but the war in Ukraine has forced an urgent rethink.
Andersson's party, the Social Democrats, have begun an internal review to debate whether Sweden should seek membership.
"This is an important time in history," said Andersson, speaking alongside Marin on Wednesday. "The security landscape has completely changed.
"We have to think about what is the best for Sweden for our security and peace."
Kremlin spokesperson Dimitry Peskov has warned Finland and Sweden against joining NATO, arguing the move would not bring stability to Europe.
Most analysts expect Finland to decide on applying for NATO membership before an alliance summit in Madrid on 29 June.