On Tuesday, NATO members signed a protocol for Finland and Sweden to join the military alliance.
The two countries submitted an application in May, breaking the long-standing non-aligned stance in response to Russia's invasion of Ukraine.
"Today is a good day for Finland and Sweden, and a good day for NATO. With 32 countries around the table in the face of the biggest security crisis in decades. We will be stronger and people will be safer, "said NATO Secretary General Jens Stortenberg.
He said, "The NATO door remains open to democracies in Europe, ready to contribute to our shared security and ready to contribute." Added.
With the signing of the Membership Protocol, each of NATO's 30 member states must ratify according to their own national procedures.
Finland and Sweden have a history of cooperating with NATO as partner countries.
"As a future member of the alliance, Sweden will contribute to the security of all allies," Sweden's Foreign Minister Ann Linde said at the beginning of Tuesday's meeting.
Finland's Foreign Minister Pekka Havisto said his country is looking forward to working with NATO allies to protect the "safe and prosperous Euro Atlantic region".
"We are strong together to uphold the principles of rule-based international order, democratic freedom and the rule of law," Harvist said.
Some information in this report is from The Associated Press and Reuters