Washington, DC – United States President Joe Biden has said he is “anxiously looking forward” to Sweden joining NATO as he hosted the northern European country’s Prime Minister Ulf Kristersson.

The White House also renewed calls for Turkey to approve Sweden’s bid to join the alliance on Wednesday in advance of a NATO summit in Lithuania next week.

“I want to reiterate: The United States fully, fully, fully supports Sweden’s membership in NATO. The bottom line is simple – Sweden is going to make our alliance stronger,” Biden told reporters before the meeting.

White House press secretary Karine Jean-Pierre also urged Sweden’s admission into NATO “as soon as possible”.

“Sweden is a strong, capable defence partner that shares NATO’s values and will strengthen the alliance and contribute to European security,” Jean-Pierre said on Wednesday as the two leaders held talks in Washington, DC.

Sweden and neighbouring Finland started seeking NATO membership last year after Russia’s full-scale invasion of Ukraine. The US-led alliance has a collective defence pact, meaning an attack on one member is considered an attack on all.

On Wednesday, Kristersson thanked Biden for his “strong support” for Sweden’s NATO bid. “We do seek common protection, but we also do think that we have things to contribute with to be a security provider for the whole of NATO,” he said.

NATO members need to unanimously agree to allow new countries into the bloc. Finland officially joined the alliance in April, but Sweden’s application is still pending.

Hungary and Turkey have not ratified Sweden’s accession, but Ankara is seen as the main hurdle. Turkey has accused Sweden of providing a safe haven to members of the Kurdistan Workers’ Party (PKK), which it considers a “terrorist” group.

In June of last year, Turkey, Sweden and Finland signed a so-called trilateral memorandum to address Ankara’s grievances about banned armed groups. Turkey, however, has said that Sweden has not fulfilled all of its commitments in the agreement.

Further complicating the issue are the two Quran-burning protests by far-right activists during demonstrations in Sweden this year that have angered Turkey.

The Swedish government has condemned the desecration of Islam’s holy book but allowed the demonstrations to proceed – with the country’s courts allowing them as free speech.

Turkish Foreign Minister Hakan Fidan criticised a Quran-burning protest last month. “Turning a blind eye to such atrocious acts is to be complicit,” he said on Twitter.

Earlier this week, Turkish President Recep Tayyip Erdogan also signalled that Ankara is sticking to its position against Stockholm.

“We have made it clear that the determined fight against terrorist organisations and Islamophobia are our red line,” he said.

For its part, Washington has rejected the burning of the Quran while calling on Turkey to approve Sweden’s NATO bid.

“The burning of religious texts is disrespectful and hurtful, and what might be legal is certainly not necessarily appropriate,” US Department of State spokesperson Vedant Patel said in June.

Meanwhile, US officials have been calling on Turkey to lift its opposition to Sweden’s NATO bid.

Kristersson’s visit to the White House as come weeks after he met Secretary of State Antony Blinken in Sweden. At that time, Blinken said he hoped Sweden’s NATO accession would be finalised before the Lithuania summit, which is set to start on July 11.