KYIV President Volodymyr Zelenskiy called on Tuesday for Ukraine to receive a political invitation to join NATO when the military alliance holds a summit in Lithuania next month.

"There is every reason for a political invitation for Ukraine to join the Alliance," he wrote on the Telegram messaging app.

Zelenskiy, whose country has been invaded by Russia, has also been demanding security guarantees from the North Atlantic Treaty Organization if Ukraine is not given membership of the alliance in the near future.

He said on Tuesday there was "a full understanding of the security guarantees for Ukraine until the moment of accession" but gave no further details.

Defence Minister Oleksii Reznikov said last week he expected Kyiv to receive a clear signal and "formula" for it to become a member of NATO at the July 11-12 summit in Vilnius.

Zelenskiy has pressed hard for Ukrainian membership of NATO but has also said he recognises it would be impossible to join while Russia's war in Ukraine is still raging.

He said on Tuesday Kyiv was working "to make the decisions of the Vilnius Summit truly meaningful."

Zelenskiy later said he had discussed Sweden's NATO accession bid in a phone call with Swedish Foreign Minister Tobias Billstrom, and added: "I also reiterated our call for crucial political decisions on Ukraine's NATO membership."

Western governments such as the United States and Germany are wary of moves they fear could take the alliance closer to entering an active war with Russia, which has long seen NATO's expansion into eastern Europe as evidence of Western hostility.

(Reporting by Anna Pruchnicka and Kyiv newsroom, Editing by Timothy Heritage)