“The meeting is an important security policy signal,” Andersson wrote on her Instagram account from Washington DC.
The two Nordic leaders boarded their flight to Washington shortly after their Nato ambassadors applied to join the alliance on Wednesday morning.
At the meeting in the White House today, the delicate security situation in both Finland and Sweden will be discussed.
The US has given security assurances to the two countries during the gap between their applications to join Nato and the accession as members, as have Britain, France, Germany, Denmark, Norway and Iceland.
“Biden Finland and Sweden are longtime, stalwart partners of the United States. By joining Nato, they will further strengthen our defence cooperation and benefit the entire Transatlantic Alliance,” Biden said in his statement.
The US would maintain its “robust exercise activity and presence” in the Baltic Sea region, he added.
“While their applications for Nato membership are being considered, the United States will work with Finland and Sweden to remain vigilant against any threats to our shared security, and to deter and confront aggression or the threat of aggression.”
Another issue on the agenda will be how to respond to Turkey’s moves to block the process until Sweden and Finland meet demands to, among other things, extradite people in Sweden the country claims are linked to terror organisations and end its embargo on weapons sales to Sweden.
The US, as the most powerful country in the alliance, could be able to put pressure on Turkey’s President, Recep Tayyip Erdoğan, to back down, or offer other concessions, perhaps over its wish to buy US F-16 fighter jets.
Andersson spoke to Biden on the phone on Friday and met him in Brussels at the end of March, but this is her first visit to Washington as prime minister.
Final approval for Sweden and Finland’s bid could take up to a year, and Russia is expected to react to the two countries joining Nato in some way.
Sweden and Finland’s decision to join the Nato alliance was applauded by Ukrainians taking part in a demonstration outside the White House.