"NATO allies have agreed that Ukraine will become a member of our alliance, but at the same time that is a long-term perspective," Stoltenberg told reporters during a visit to Finland's capital Helsinki, AFP reported.
Stoltenberg added that "the issue now is that Ukraine prevails as a sovereign independent nation, and therefore we need to support Ukraine."
Since the start of the Ukraine war almost a year ago, President Volodymyr Zelensky has urged the US-led military alliance to grant his country a fast-track membership.
Ukraine applied for EU membership in February 2022, shortly after it was attacked by the Russian army, and was granted candidate status in June.
When the war ends "we need to ensure that history doesn't repeat itself," Stoltenberg told a press conference with Finnish prime minister Sanna Marin.
MNA/PR