How does a country join NATO?

The world’s most powerful military alliance has 31 members. Sweden is poised to make it 32, and Ukraine wants in as well.

An empty flagpole
An empty flagpole for Finland stands between the national flags of France and Estonia outside NATO headquarters in Brussels shortly before Finland met all the requirements to join the alliance [File: Virginia Mayo/AP]

On the final day of the NATO summit in Lithuania’s capital, Vilnius, the military alliance’s chief, Jens Stoltenberg, has told reporters, “Ukraine is now closer to NATO than ever before.”

In a joint press conference with Ukrainian President Volodymyr Zelenskyy, Stoltenberg said: “I look forward to the day we meet as allies.”

While Zelenskyy described the results of the NATO summit as good after allies pledged more military aid to Ukraine, he said an ideal situation would have been an invitation to Kyiv to become a member of the alliance.

Here is how a country joins NATO:

NATO history and expansion

Since its creation in 1949, the world’s most powerful military alliance has increased its membership from 12 to 31 countries through nine rounds of enlargement.

NATO’s founding members were Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom and United States.

Their aim was to curb Soviet expansion and encourage political integration in Europe.

INTERACTIVE - NATO TIMELINE OF MEMBER states 2023 FinlandHow does a country join NATO?

Once a country is invited to join the alliance from all of its members, a formal process of accession talks begins.

INTERACTIVE - how does a country join NATO

Countries interested in joining NATO are asked to agree to a membership action plan tailored to the individual country and potentially requiring political, legal, military and security reforms.

The following steps outline the process of joining NATO:

  • Step 1: Accession talks with NATO in Brussels. This involves discussions to determine if an invitee meets the requirements of NATO membership.
  • Step 2: Letter of intent sent to NATO secretary-general. This involves an invitee providing written confirmation of its acceptance of NATO commitments and a timetable of reforms.
  • Step 3: Accession protocols signed by NATO members. This step allows an invitee to become a party to the Washington Treaty, which formed NATO.
  • Step 4: Accession protocols ratified by NATO member governments according to their national procedures. In the US, this requires a two-thirds majority of the Senate to pass the required legislation.
  • Step 5: Secretary-general invites the potential member to accede to the treaty.
  • Step 6: Invitee accedes to the treaty according to their national procedures.
  • Step 7: After depositing their instruments of accession with the US Department of State, an invitee becomes a NATO member.

What are the military requirements?

NATO is resourced through the direct and indirect contributions of its members.

For 2023, NATO’s military budget was set at 1.96 billion euros. Member countries contribute to the budget based on a cost-sharing formula derived from the gross national product of each country.

In 2006, the alliance’s defence ministers agreed to commit a minimum of 2 percent of their GDPs to defence spending. So far, only eight countries adhere to this guideline: Greece, the US, Lithuania, Poland, the UK, Croatia, Estonia and Latvia.

Which countries are in the EU as well as in NATO?

There are 22 countries that are members of both the European Union and NATO: Belgium, Bulgaria, Croatia, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Luxembourg, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia and Spain.

There are five states that are in the EU but not the military alliance: Austria, Cyprus, Ireland, Malta and Sweden.


Sweden applied to join NATO along with Finland in May 2022. Finland became the military alliance’s 31st member in April. However, Sweden’s bid was stalled by Turkey.

Stoltenberg announced on Monday that Turkish President Recep Tayyip Erdogan agreed to forward Sweden’s membership bid to Turkey’s parliament.

Ukraine has voiced its desire to join NATO and the EU. Russia has long objected to Ukrainian membership in the military alliance.

On Tuesday, Zelenskyy called the lack of a time frame for membership “unprecedented” and “absurd”.

Al Jazeera’s James Bays, reporting from the summit in Vilnius, said ​​Zelenskyy also defined what he thought NATO’s communique on Ukraine’s membership meant and compared Kyiv’s NATO membership pathway to its EU membership.

“He said being made a candidate of the EU doesn’t mean ‘I’m an EU member,’ but it shows a message to Russia and my people. He said the same would apply if an invitation was issued to Ukraine to be a NATO member,” Bays said.

Source: Al Jazeera