Turkey's ratification would leave Hungary as the last holdout in the accession process, which Sweden and its neighbour Finland began in response to Russia's invasion of Ukraine nearly two years ago.

Citing its own source, NTV television channel said the vote would be held this week, without providing an exact date.

Finland became the 31st member of the US-led defence alliance last April, roughly doubling the length of NATO's border with Russia.

But Turkish President Recep Tayyip Erdogan had put up a series of roadblocks to Sweden's membership.

Erdogan lifted his personal objections after Stockholm last year cracked down on Kurdish groups that Ankara calls terrorists.

The Turkish parliament's foreign affairs committee approved the bid last month.

But Erdogan has since made a series of new demands, including a request for Washington to follow through on its pledge to deliver a batch of F-16 fighter jets for Turkey's ageing air force.

Erdogan last month discussed his demands by telephone with US President Joe Biden, who argued that Turkey's request could win the required congressional approval if Sweden's NATO accession goes through.