The Oval Office meeting kicks off a string of diplomatic events for Biden centered on NATO. He leaves Sunday for one-day trip to close ally Britain, then attends the annual NATO summit in Vilnius and finishes up with a stop in the alliance's newest member Finland.

Finland and Sweden both dropped their official neutrality to request NATO entry in response to Russia's 2022 invasion of neighboring Ukraine. Biden sees the bloc's expansion and its mammoth efforts to arm and support Ukraine's forces as a strategic defeat for Moscow -- and his own biggest diplomatic achievement.

But expansion of NATO requires unanimous ratification from the existing 31 members. Unlike Finland, which won quick approval from the world's most powerful defensive alliance, Sweden's entry remains held up by two members, Turkey and Hungary.

Biden and Kristersson will reiterate "their view that Sweden should join NATO as soon as possible," the White House said in a statement.

"I am delighted that President Biden is inviting us to a meeting next week, before the NATO summit in Vilnius the following week," Kristersson said in a statement. "The focus of the visit will be on Sweden's NATO accession."

In addition to discussing efforts to bolster Ukraine during its difficult counteroffensive to oust Russian troops occupying swaths of the east and south of the country, the two leaders will also talk about transatlantic coordination on China, climate change and emerging technologies.

- Turkey refuses 'pressure' -

Western officials had hoped to formally welcome Sweden into the bloc by the NATO summit next Tuesday.

Turkish President Recep Tayyip Erdogan, however, has frustrated Western leaders by linking approval for Sweden to demands that Stockholm crack down on members of opposition Kurdish movements, such as the Kurdistan Workers' Party PKK, which Turkey says is a terrorist group.

Sweden says it met those demands, but another flashpoint has emerged over a protest outside a Stockholm mosque where an Iraqi man set fire to pages from the Koran.

On Tuesday, Turkish Foreign Minister Hakan Fidan rejected making the NATO summit a deadline, saying "we never approve of the use of time pressure as a method."

Hungary has indicated that it will follow Turkey's lead in the dispute.

Hungarian Foreign Minister Peter Szijjarto said Tuesday he had been holding regular consultations with Fidan about Sweden.

Top diplomats from Turkey and Sweden will meet on Thursday at NATO headquarters in Brussels.

The diplomatic activity comes as Ukraine is in the early phases of a long-promised push to try and liberate territories occupied by Russia.

The Biden administration is hoping that success in that offensive will buoy public opinion ahead of the 2024 presidential election, where generous US aid to Ukraine may become a contentious issue.