Finland will officially become the 31st member of NATO on Tuesday, a step that will make Finland safer and the alliance stronger, NATO Secretary-General Jens Stoltenberg announced Monday.

"From tomorrow (Tuesday), Finland will be a full member of the alliance," Stoltenberg told reporters in Brussels.

Stoltenberg said that Türkiye, the last country to have ratified Finland’s membership, will hand its official texts to U.S. Secretary of State Antony Blinken on Tuesday as NATO foreign ministers gather in Brussels.

Stoltenberg said he would then invite Finland to do the same.

A flag-raising ceremony to add the Finnish flag to those of the other members will take place at NATO headquarters on Tuesday afternoon.

"It will be a good day for Finland's security, for Nordic security and for NATO as a whole," Stoltenberg said.

"Sweden will also be safer as a result," he added, reiterating his wish to see the Nordic country’s accession completed as soon as possible.

Russian President Vladimir Putin's all-out invasion of Ukraine last year upended European security and pushed Finland – and its neighbor Sweden – to drop decades of non-alignment and seek to join NATO's protective umbrella.

Objections from Türkiye and Hungary held up Helsinki's bid for months and are still blocking Stockholm. The Parliament in Ankara cleared the final obstacle for Finland with a vote last week.

For a new country to join NATO, each of the alliance's existing members needs to give its formal approval.

All 276 lawmakers present in Türkiye’s Parliament last Thursday voted unanimously in favor of Finland’s bid, days after Hungary’s Parliament also endorsed Finland’s accession, marking one of the fastest-progressing procedures in NATO’s 74-year history.

While Finland is fast on its way to raising its flag in Brussels, Sweden's membership is still pending Turkish ratification due to several sticking points, among them Ankara's concerns over what it says is a lack of cooperation in fighting terrorism "in all its forms and manifestations, against all threats to national security."

Hungary has also not yet voted to ratify Sweden's NATO membership, citing "an ample amount of grievances" in a statement related to EU budget funds, among other things.

After hosting Finnish President Sauli Biinisto in Ankara on March 17, Erdoğan said Türkiye would start the process for admitting Finland into the alliance based on the Nordic country’s effort to keep its promises as part of the trilateral memorandum the sides inked in Madrid last June.

For Sweden’s NATO odds, Erdoğan said Türkiye was "not yet ready" to approve its bid but assured Ankara and Stockholm would "continue discussing terrorism-related issues."