US President Joe Biden has expressed support for Turkey's acquisition of F-16 fighter jets, the White House said, while Secretary of State Antony Blinken stressed that his country does not link the sale of fighter jets to Ankara to the issue of Sweden's accession to NATO.

A White House statement added that Turkey's approval of Sweden's accession to NATO was not a condition for Ankara to receive F-16 jets.

Secretary of State Antony Blinken on Tuesday urged Turkey to immediately finalize the approval of Sweden's NATO application, saying the northern European country had already taken important steps to address Ankara's objections to its bid.

Blinken said Washington was continuing to work to complete Sweden's accession before the NATO summit in mid-July, speaking at a joint news conference with Swedish Prime Minister Ulf Christersson in the northern Swedish city of Lulu.

The US secretary's comments came hours after Turkey called on Sweden to prosecute those responsible for raising the flag of a banned group on top of the parliament building in Stockholm, on the day of Turkey's run-off election that extended Turkish President Recep Tayyip Erdogan's rule.

Biden said on Monday that he confirmed - in a phone call with Erdogan during which he congratulated him on winning the presidential election - that Washington wants Ankara to abandon its objection to Sweden's request to join NATO.

Biden told reporters before leaving the White House for Delaware: "I spoke to Erdogan and congratulated him, and he still wants some solution regarding the F-16. I told him we wanted to deal with Sweden, so let's end it. So we're going to get back in touch," he said, adding: "We'll talk more about that next week."

Sweden and Finland applied to join NATO last year, abandoning longstanding policies of military non-alignment following Russia's war in Ukraine.

Turkey approved Finland's NATO application in late March but continued to oppose Sweden's accession, saying Stockholm was harboring members of armed groups Turkey classifies as terrorist groups. Hungary also did not accede to Sweden's request.

The consent of all NATO members is a condition for any new member to join. Turkey and Hungary have so far not agreed to Stockholm's request.

Turkey is seeking to buy $16 billion worth of F-20 fighter jets from the United States, but the sale has stalled due to congressional objections, despite the Biden administration's repeated statement that it supports the deal. Congressional reticence on the deal stems from its objection to what it says is Ankara's human rights record and Syria policy.

But Congress this year approved a much smaller $259 million package, including an upgrade to avionics software for Turkey's current fleet of F-16 fighter jets, days after Ankara ratified Finland's entry into NATO.