For step five, all member states, after completing their ratification processes, issue a notification to the US – which hosts the treaty – that they have accepted the protocols that envisage the accession of the new member state.
When all these stages are completed in step six, the NATO secretary-general invites the new member to join the alliance.
Finally, the new member completes its own national legal process and submits its accession document to the US, which has kept the Washington Treaty and becomes a NATO member.
3 countries still waiting
Some countries have expressed the intent to become NATO members, but their application has not yet been approved. They include Bosnia and Herzegovina, Ukraine, and Georgia.
At the 2008 NATO summit in Romania's capital Bucharest, it was agreed that Georgia and Ukraine would become NATO members in the future.
Since then, the two countries are called as partners as both of them are participating in the NATO operations and the alliance supports them to enhance their defense capacity.
However, neither country was given a date.
In 2010, the Balkan nation of Bosnia and Herzegovina was invited to NATO's Membership Action Plan.
