Finnish President Sauli Niinistö and Prime Minister Sanna Marin had announced the intention to join on Sunday, and Parliament's approval wasn't officially required. However, both Niinistö and Marin stressed that it was important for the Parliament to weigh in on the NATO bid, described by the Finnish head of state as "historic."
Finland is expected to sign a formal application and file it to NATO headquarters in the coming days.
At the same time, Sweden on Tuesday already signed a formal request to join NATO, a day after the country announced it would seek membership.
The moves by the two countries, ending Sweden's more than 200 years of military nonalignment and Finland's nonalignment after World War II, have provoked threats from the Kremlin.
Finnish President Sauli Niinistö arrived in Sweden for an official two-day visit and was welcomed by Sweden's King Carl XVI Gustaf and Queen Silvia, who had invited him. Niinistö addressed Sweden's Parliament and said, "we took peace for granted; on Feb. 24 the peace was broken. Our old ways of handling things no longer correspond to the new situation, our relations with Russia have changed."
All 30 current NATO countries must agree to accept new members. While the acceptance is expected to be relatively straightforward by most current NATO members, Turkey has potentially complicated their accession by saying it cannot allow them to become members because of their perceived inaction against exiled Kurdish militants. Turkish President Recep Tayyip Erdogan has accused the two Nordic countries of refusing to extradite "terrorists" wanted by his country.
