(AFP) - President Volodymyr Zelensky told allies Thursday Ukraine must be in a position of strength before any peace talks with Russia, as he explained his "victory plan" to EU leaders and NATO defence chiefs in Brussels.

More than two and a half years into the war, Kyiv is slowly but steadily losing new territory in its eastern Donbas region and under mounting pressure to forge an exit strategy -- which it says must start with ramped-up Western support.

"Ukraine is ready for real diplomacy, but for it, we must be strong," Zelensky said as he headed into talks with the EU's 27 leaders. "A forcefully imposed truce instead of fair peace never provided security."

"Russia will resort to diplomacy only when it sees that it cannot achieve anything by force," Zelensky added. "This is the plan. This is exactly what's needed, and we must create the right conditions to end this war."

After the EU summit Zelensky was to join defence ministers for the first of two days of talks between NATO's 32 member states, holding a joint press conference with Alliance chief Mark Rutte.

While calling it a "strong signal," the NATO secretary-general cautioned ahead of time he was not endorsing Zelensky's "whole plan" -- which calls first and foremost for an immediate invitation to join the US-led alliance, a plea widely seen as unrealistic.

Zelensky's plan also rejects any territorial concessions, calls for Western allies to lift restrictions on using donated long-range weapons to target Russian military sites, and suggests deploying a "non-nuclear strategic deterrence package" on Ukrainian territory.

The Ukrainian leader has traveled in recent weeks to Washington, Paris, Berlin, Rome and London to defend his plan -- unveiled to Ukrainian lawmakers Wednesday -- but it has yet to earn backing from Western capitals.

- 'Position of strength' -

NATO countries have declared Ukraine to be on an "irreversible path" to membership.

But the United States and Germany have led opposition to immediate entry, believing it would effectively put the alliance at war with nuclear-armed Russia.

Rutte reiterated the Alliance line on Thursday saying only that "Ukraine will be a member of NATO in the future."

Washington's ambassador to NATO, Julianne Smith, was blunter ahead of the Brussels talks, saying: "We are not at the point right now where the alliance is talking about issuing an invitation in the short term."

The US position is unlikely to shift whether Donald Trump or Kamala Harris wins the White House on November 5 -- though there are fears a second Trump term could upend the support Ukraine receives from NATO's biggest power.

Insiders agree the elephant in the room at the NATO talks will be the contest playing out across the Atlantic, with one diplomat saying the Alliance was in "waiting mode."

But Ukraine's allies are well aware that time is of the essence, with the outlook on the battlefield bleak.

Rutte said NATO's focus remained on keeping "massive military aid moving into Ukraine" in order "to make sure that if ever one day Zelensky and his team decide to discuss with Russia how to end this, that he will do this from a position of strength."

But despite Ukraine's plea for stepped-up air defence systems -- as Russian forces pound its cities and infrastructure -- no new announcements were expected from NATO this week.

- 'Various ways to define victory' -

Some at NATO argue the setbacks inflicted on Russian President Vladimir Putin since the invasion are already sufficient to justify seeking a negotiated outcome -- rather than letting the war drag on indefinitely.

"There are various ways to define victory or to define defeat," said one NATO official.

On the eve of the NATO meeting, German Chancellor Olaf Scholz called for exploring ways to end the war -- potentially including talks with Putin.

But according to an alliance diplomat, other voices still fear that anything short of an outright victory for Kyiv would spell "disaster" -- ensuring that an emboldened Russia does not stop there.

© Agence France-Presse