US President Joe Biden quipped to reporters about how Russian President Vladimir Putin unified Europe in opposition against Russia in a press conference concluding the Nato summit in Madrid on Thursday.

"[Putin] wanted the Finlandisation of Europe. He got the Natoisation of Finland," the US president remarked.

Finlandisation refers to Finland's policy of non-alignment during the Cold War and is a widely used term in the field of international relations describing similar geopolitical situations. The phrase in Finland is often viewed as pejorative and an oversimplification of the country's history.

Biden commented on Finland and Sweden joining Nato as "a historic act" and highlighted the gravity of the two Nordic countries abandoning what he referred to as their "long tradition of neutrality".

The US president also showed his commitment to Nato unity and support for Ukraine. He claimed that Putin attempted to weaken Nato.

"Putin thought he could break the transatlantic alliance.he expected our resolve to fracture," Biden said, adding, "but, he's getting exactly what he did not want."

Biden went on to say that the two Nordic countries joining Nato would bolster the alliance.

"With the addition of Finland and Sweden, we'll be stronger than ever. They have serious militaries, both of them. We're going to increase the Nato border by 800 miles [1300 kilometres] along the Finnish-Russian border," Biden stated to reporters.

Biden's statements came at a press conference concluding a two-day Nato summit in Madrid in which Finland and Sweden were formally invited to join Nato.

In addition, Turkish President Recep Tayyip Erdogan told the press that Finland and Sweden need to abide by the stipulations laid out in the trilateral agreement in order for Turkey to approve the Nordic countries to join the alliance. The agreement has been interpreted differently in Turkey, Finland and Sweden.

Earlier on Thursday, Nato Secretary-General Jens Stoltenberg also responded to comments Putin had made regarding an increased Nato military presence in Finland and Sweden.