CNN said, quoting a NATO official, that the chances of Turkish President Recep Tayyip Erdogan changing his position on Sweden's membership in the alliance are few, ahead of the upcoming summit of NATO leaders in Lithuania next July.
The official added that Sweden and Finland should seek membership individually, explaining that the Turkish position on the two countries' membership in the alliance feeds the Kremlin's narrative of a division within it.
Sweden and Finland applied to join NATO last year in the wake of Russia's war on Ukraine, but faced objections from Turkey.
Turkey asked the two countries to cooperate in several files before granting its approval to membership, especially the extradition of wanted persons from the Kurdistan Workers' Party (PKK) and the Fethullah Gulen group, which Ankara accuses of masterminding the failed coup attempt in 2016.
Joining NATO requires the approval of all 30 member states, including Turkey.
The atmosphere between Turkey and Sweden has been tense recently after the Swedish authorities allowed the burning of the Holy Qur'an in front of the Turkish embassy in Stockholm.
Ankara has hinted in recent days that it will agree to Finland's accession only unless Sweden takes further steps to meet Turkish demands, while Finnish President Sauli Niinisto said that his country will follow its path to join NATO even if Sweden's request falters.