Dutch Defense Minister Ruben Brekelmans said NATO member-states would need to discuss and agree on conditions for Ukraine to receive an invitation to join the military bloc in response to President Volodymyr Zelenskyy's "victory plan."

Zelenskyy presented the five-point plan publicly for the first time this week, including a call for an immediate NATO invitation to make clear to Russian President Vladimir Putin that Moscow's invasion would end with geopolitical defeat.

NATO has declared that Ukraine will become a member of the alliance one day but also said Kyiv cannot join while at war, as that could lead to a direct conflict between NATO and Russia.

Alliance leaders have so far avoided a direct response to Zelenskyy's new push for an invitation.

Brekelmans, whose country is among NATO's 32 members, said there were "very different opinions" in the alliance on the issue.

To reach the necessary consensus, he said, allies would need to agree on clear criteria that Ukraine would need to meet to get an invitation and others required to later become a member.

"If you don't have that clarity upfront, I don't see (that) 32 allies agree to granting an invitation," he told reporters after a meeting of NATO defense ministers in Brussels.

Asked what conditions Ukraine might need to meet, Brekelmans cited fighting corruption.

"If you want to modernize the Ukrainian armed forces, and have involvement of other countries, then I can imagine that you also want to assess the progress that Ukrainians make on that dimension," he said.