Recep Tayyip Erdogan’s objections have held up the process of Sweden joining the military alliance since last year.
But on Monday night, Mr Stoltenberg said the Turkish president had agreed to send Sweden’s Nato accession protocol to the Turkish Parliament “as soon as possible.”
“I’m glad to announce … that President Erdogan has agreed to forward the accession protocol for Sweden to the grand national assembly as soon as possible, and work closely with the assembly to ensure ratification,” he told a news conference.
He described it as a “historic step”, but stressed that a “clear date” could not be given for when Sweden could join the military alliance.
The announcement came after talks with Mr Erdogan and Swedish Prime Minister Ulf Kristersson on the eve of a Nato summit in Lithuania.
Sweden and Finland applied to join Nato last year, casting aside policies of military non-alignment after Russia’s invasion of Ukraine.
But applications to the alliance must be approved by all Nato members. While Finland’s was given the go-ahead in April, Turkey and Hungary have held off on clearing Sweden’s bid.
Mr Erdogan had accused Sweden of harbouring members of militant groups, mainly supporters of the Kurdistan Workers Party (PKK).
But Sweden has said it has fulfilled all the demands agreed upon in negotiations with Turkey over joining Nato, including introducing a new bill that makes being a member of a terrorist organisation illegal.
Stockholm has been working hard at its bid ahead of the Nato summit in Vilnius, together with the United States and its allies, urging Turkey to abandon its opposition.
Meanwhile, Hungarian Prime Minister Viktor Orban’s chief of staff said on Thursday that Budapest would not block Sweden’s Nato membership ratification.
