US President Joe Biden is set to meet Finland's President Sauli Niinisto and Sweden's Prime Minister Magdalena Andersson in Washington to discuss their Nato membership bids, APA reports citing the BBC.
The US is backing both nations' efforts to join the Western defense 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.
"I warmly welcome and strongly support the historic applications from Finland and Sweden for membership in Nato," Biden said in a statement on Wednesday.