NATO chief Jens Stoltenberg said Friday that Finland would formally become a member within days.

"I look forward to raising Finland's flag at NATO HQ in the coming days. Together we are stronger and safer," Stoltenberg wrote on Twitter.

After months of delays, Turkey's parliament Thursday removed the last hurdle for Finland by becoming the last member of the US-led military alliance to ratify its application.

Stoltenberg said in separate statement that "Finland has highly capable forces, advanced capabilities, and strong democratic institutions."

"So Finland will bring a lot to our alliance," he said.

NATO foreign ministers are meeting at the alliance's headquarters in Brussels next week, when it is expected the membership could be formalised.

"I look forward to also welcoming Sweden as a full member of the NATO family as soon as possible," he also said.