NATO chief says Finland and Sweden being on the cusp of joining alliance shows Putin made a 'huge mistake' by invading Ukraine

• NATO chief Jens Stoltenberg told CNN that Putin made a "huge mistake" by invading Ukraine.
• Stoltenberg was pointing to the historic additions of Finland and Sweden to NATO — a consequence of Russia's invasion.

NATO Secretary-General Jens Stoltenberg in a new interview with CNN said this week marks a "victory" for the alliance with Finland and Sweden on the verge of becoming new members, while accusing Russian President Vladimir Putin of underestimating Ukraine and Western unity.

Putin "wanted less NATO" by invading Ukraine, Stoltenberg told CNN's Christiane Amanpour, but "what he's getting now is more NATO, and two new NATO members."

NATO formally invited Sweden and Finland to join the alliance as it held a summit in Madrid this week. The two Nordic countries have been military non-aligned for decades, but Russia's invasion of Ukraine pushed them to pursue NATO membership. Finland shares an 830-mile border with Russia, making it a particularly significant addition to NATO.

At the NATO conference, the US announced plans to deploy two more ballistic missile defense-capable destroyers to Spain, a permanent US garrison in Poland and two more F-35 stealth fighter squadrons to the UK, among other moves.

Amid these developments, Stoltenberg said Putin made "a big and huge mistake" by ordering Russia's invasion of Ukraine.

As Russia gathered tens of thousands of troops on Ukraine's border in the lead-up to the full-scale invasion in late 2021 and early 2022, the Kremlin made demands for binding security guarantees from the West. Among other things, Moscow called for NATO to permanently bar Ukraine and Georgia from joining the alliance. NATO vehemently rejected this demand, stating that its open-door policy was non-negotiable.

Indeed, Putin has railed against NATO enlargement for years, and has partly blamed Russia's unprovoked military offensive in Ukraine on the alliance. But the Russian leader in recent days has sought to downplay the significance of Finland and Sweden joining NATO.

"If Finland and Sweden wish to, they can join. That's up to them. They can join whatever they want," Putin said in a visit to Turkmenistan this week. But the Russian leader also warned the two Scandinavian countries against installing NATO military infrastructure and hosting "military contingents" within their borders.

Though Stoltenberg sounded bullish about enlarging NATO to include Finland and Sweden, he also underscored that the alliance is still cognizant of the "difficulties" Ukraine continues to face as the war rages on — particularly in the eastern Donbas region. The NATO chief emphasized that the alliance is aware of the need for it to do "even more" to ensure Ukraine "prevails" in the fight against Russia.