BRUSSELS, BELGIUM - MAY 19: Prime Minister of Montenegro, Milo Dukanovic and Secretary General of NATO Jens Stoltenberg (not seen) hold a joint press conference in Brussels, Belgium on May 19, 2016. NATO have signed an accession agreement with Montenegro, which becomes the 29th member of the alliance. (Photo by Dursun Aydemir/Anadolu Agency/Getty Images)
