NATO members are to sign the accession protocols necessary to invite Sweden and Finland to join the alliance in a ceremony on Tuesday at the alliance’s headquarters in Brussels, transmits MIA.

The Swedish Foreign Minister Ann Linde and her Finnish counterpart Pekka Haavisto are set to take part alongside representatives of the current 30 members of the Western military alliance.

The protocols permit NATO Secretary General Jens Stoltenberg to formally invite Sweden and Finland to join the alliance however a ratification process may see both Nordics countries continue to wait. Alliance members must pass the invitation protocols, a process normally involving the national parliaments. This is estimated to last another six to eight months before Sweden and Finland can join.

The invitation protocols could have been signed earlier, however Turkey only agreed to drop its opposition to the Nordic countries’ membership application in a last-minute deal ahead of the start of the NATO summit in Madrid last week.

Ankara had accused both countries of supporting the Kurdistan Workers’ Party (PKK) and the YPG, a Kurdish militia based in Syria, both of which Turkey classifies as terrorist groups. Both countries disputed the charges. Shaken by the Russian invasion of Ukraine, Sweden and Finland applied to join NATO on May 18. Turkey however blocked their bid for weeks over concerns linked to terrorism. New NATO membership requires unanimity.

A breakthrough was secured after the three leaders agreed to cooperate in a series of counterterrorism efforts including extradition agreements and pledges to end arms embargoes.