“I’m confident of course that Sweden will be a member, and then we’re working for that to happen as early as possible,” Stoltenberg said at a meeting of Nato foreign ministers in Oslo.
Stoltenberg said he had already spoken to Turkish President Recep Tayyip Erdoğan by phone earlier this week to “highlight the importance of making progress” on Sweden’s membership.
Turkey and Hungary are the only Nato countries that have yet to ratify Sweden’s membership bid. Finland formally joined the alliance in April.
Erdoğan, who was re-elected Sunday for another five-year term as Turkey’s president, has accused Sweden of being a haven for “terrorists”, especially members of the Kurdistan Workers’ Party (PKK).
Swedish Foreign Minister Tobias Billström said Stockholm had fulfilled “all the commitments” to join Nato and urged Turkey and Hungary to allow his country into the alliance.
“It is time for Turkey and Hungary to start the ratification of the Swedish membership to Nato,” he said.
“This was never a sprint, it’s a marathon, and we now see the end of it.”
Billström pointed to new terror legislation, which will enter into force in Sweden on Thursday, as the last step under an accord signed with Turkey last year.
Billström said he hoped to see a big step made towards membership at a meeting with representatives of Turkey in the coming weeks.
“Following that meeting, the ratification will happen,” Billström insisted.