US President Joe Biden met with Swedish Prime Minister Magdalena Andersson and Finnish President Sauli Niinistö on Thursday morning in Washington to discuss their NATO membership applications.

"Having two new NATO members in the high north will enhance the security of our alliance and deepen our security cooperation across the board," Biden said.

"New members joining NATO is not a threat to any nation," the US President added.

It comes as Turkish President Recep Tayyip Erdogan vowed Ankara would continue to block the Swedish and Finnish bids "in a determined fashion," while reiterating his claims that Sweden is a "terror haven."

Why would Sweden and Finland joining NATO be significant?

Sweden and Finland, while firmly in the Western camp, have traditionally followed a policy of nonalignment with NATO to avoid drawing the ire of Moscow.

However, Russia's invasion of Ukraine has changed the security calculus in northern Europe, leading to the landmark policy shift.

The military commanders of NATO countries met in Brussels earlier on Thursday a day after receiving the membership applications from Sweden and Finland.

NATO Secretary-General Jens Stoltenberg said it was a "crucial and dangerous time for Euro-Atlantic security."

He added that although Russia's war in Ukraine has changed the security environment, President Vladimir Putin was failing in his strategic objectives.

"Ukraine stands, NATO remains strong, and trans-Atlantic unity is solid," Stoltenberg said.

The defense heads meeting comes ahead of a major NATO summit planned for June in Madrid, during which NATO will adopt a new "strategic concept."

Why is Turkey blocking Sweden and Finland's NATO bid? 

The row hinges on what Ankara perceives as Swedish and Finnish support for Kurdish political parties like the PKK as well as the Fetullah Gulen movement, the latter of which the Turkish governnment accuses of instigating the 2016 coup.

They are considered terrorist organizations in Turkey. The PKK is considered terrorist by the EU, too.

NATO membership requires consensus from all 30 member states.

"NATO is a security alliance and we cannot accept terrorists to be in it," Erdogan also said.

However, Stoltenberg said that Turkey's "concerns" were being addressed.

"It is not uncommon in NATO to have differing opinions on major decisions. We have much experience in NATO, when there is a difference of opinion, of sitting down and finding solutions," he told journalists in Copenhagen, where he had met with Danish Prime Minister Mette Frederiksen and Defense Minister Morten Bodskov.

NATO leaders confident Sweden, Finland will join

Stoltenberg reiterated that he is confident the dispute will be resolved and Sweden and Finland will join the alliance soon.

German Chancellor Olaf Scholz said on Thursday that Germany was doing everything possible to make the bids succeed.

At a news conference with his Dutch counterpart Mark Rutte, Scholz reiterated that Germany welcomed the Nordic countries' bids and said he had the impression many other countries shared his view.

"If you identify a general will, then it is that Sweden and Finland should quickly become members so I am confident that the many efforts that are underway to enable a joint decision will be successful," Scholz said.

wmr/rt (Reuters, AFP, AP)