BRUSSELS - NATO foreign ministers decided Wednesday to invite Montenegro to become the 29th member of the alliance and to start accession talks in early 2016, the security organization said.

NATO Secretary General Jens Stoltenberg said the "historic" decision was "an important step in the Euro-Atlantic integration of the entire Western Balkans region and it makes clear that NATO keeps its door open, to complete our vision of a Europe whole, free and at peace."

The alliance will continue to monitor progress in these areas during the accession talks and the ratification process, he added.

NATO and Montenegro have worked closely together through the Membership Action Plan since 2009, which helps nations prepare for possible future membership.

As a precondition for membership, Stoltenberg said it was important for Montenegro to continue "on defense adaptation, on domestic reform, especially rule of law, and to continue to make progress in demonstrating public support for Montenegro's NATO membership."

In September 2014, NATO announced at the Wales Summit that it would assess whether to invite Montenegro to join the alliance by the end of 2015.