KYIV (Reuters) - Ukraine's membership of NATO is "achievable", but Kyiv will have to fight to persuade allies to make it happen, President Volodymyr Zelenskiy told Ukrainian diplomats in a speech on Sunday.

Ukraine has repeatedly urged NATO to invite Kyiv to become a member. The Western military alliance has said Ukraine will join its ranks one day but has not set a date or issued an invitation.

Moscow has cited the prospect of Ukraine joining NATO as one of the principal justifications for its 2022 invasion. Kyiv says membership in the Western alliance's mutual defence pact, or an equivalent form of security guarantee, would be crucial to any peace plan to ensure that Russia does not attack again.

"We all understand that Ukraine's invitation to NATO and membership in the alliance can only be a political decision," Zelenskiy told diplomats at a gathering in Kyiv. "Alliance for Ukraine is achievable, but it is achievable only if we fight for this decision at all the necessary levels."

Zelenskiy said allies needed to know what Ukraine can bring to NATO and how its membership in the alliance would stabilise global relations.

Last week Zelenskiy urged European countries to provide guarantees to protect Ukraine after the war with Russia ends and said Ukraine would ultimately need more protection through membership of the alliance.

(Reporting by Pavel Polityuk; Editing by Peter Graff)