US President Joe Biden is set to meet Finland’s President Sauli Niinisto, and Sweden’s Prime Minister Magdalena Andersson in Washington on Thursday to discuss their Nato membership bids.
The US is backing both nations’ efforts to join the Western defence alliance. If they succeed, Nato will grow to 32 members.
The two Nordic countries made applications in the light of Russia’s invasion – drawing warnings from the Kremlin that the move would not bring stability to Europe.
Finland shares a 1,300km (800-mile) border with Russia.
Turkey is opposing the two countries’ applications, accusing them of harbouring anti-Turkish extremists.
But the UK and several other Nato nations have offered security assurances to Finland and Sweden while their applications are considered, pledging to assist them in the event that they face aggression.
“I warmly welcome and strongly support the historic applications from Finland and Sweden for membership in Nato,” Biden said in a statement on Wednesday.