It is "absolutely possible" to decide on Sweden's NATO membership before the alliance's summit scheduled to take place on 11-12 July 2023, in Lithuania's capital, Vilnius, NATO Secretary General Jens Stoltenberg said Tuesday, two days after re-electing Turkey's president who is opposed to the idea.

Stoltenberg told reporters in Oslo on the eve of a NATO foreign ministers' meeting that there are no guarantees, "but it's absolutely possible to reach a solution and enable the decision on full membership for Sweden by then."

Read: Turkey, Sweden, Finland to Discuss NATO membership in Brussels

"We don't have any certainty. Of course we are speaking about sovereign decisions by national parliaments," he said, adding that there was "a window now especially after the Turkish elections and with a Turkish parliament being constituted."

"Of course it is possible and we are working hard for this to happen as soon as possible," Stoltenberg noted.

On his part, US Secretary of State Antony Blinken called on Turkey's re-elected leader to drop his objections to Sweden's membership in NATO, urging movement on ratification before an alliance summit in July. 

Two days after President Recep Tayyip Erdogan won the Turkish elections, Blinken said on a trip to Sweden that Stockholm had addressed Turkey's concerns over joining the group. 

"The time is now to finalise Sweden's accession," Blinken told a news conference with Prime Minister Ulf Kristersson in the northern Swedish city of Lulea.

"We urge both Turkey and Hungary -- which also has not yet ratified -- to ratify the accession as quickly as possible," Blinken said.

"There is no reason for any further time. Sweden is ready now."

"We look forward to this process being completed in the weeks ahead. We have no doubt that it can be and that it should be and we expect it to be," Blinken said, declining to say if the process would be complete before the July 11-12 NATO summit in Vilnius.

Last week, faced with opposition from both Turkey and Hungary, the Swedish government contemplated deferring the objective of joining NATO from the July summit to the bloc's conference in Washington next April, according to numerous sources.

Hungary-Sweden relations are strained and must improve before the Nordic country's NATO membership application is granted, Hungarian Prime Minister Viktor Orban said, addressing the Qatar Economic Forum.

Read more: Relations with Sweden 'awfully wrong': Orban

Stoltenberg further added that he is in "constant contact" with Turkish authorities in an attempt to get the final obstacles to Sweden's accession lifted.

Sweden and its neighbor Finland applied to join NATO last year, citing changes in the European security picture as a result of the Ukraine crisis. While Finland went on to become a member, Turkey and Hungary have stymied Sweden's bid, with Budapest citing grievances over Stockholm's criticism of Orban's record on democracy and the rule of law, and Ankara accusing Sweden of harboring what it sees as Kurdish terrorists and, most recently, meddling in Turkish elections.