Ukraine's President Volodymyr Zelensky has pressed his case for the country to be part of NATO and urged the military alliance to provide security guarantees if membership is not possible for now.
Joining a meeting of European leaders in Moldova, including Taoiseach Leo Varadkar, Mr Zelensky said he was seeking to bolster Western support ahead of Ukraine's expected counteroffensive against Russia's invasion.
France and Germany both expressed support for the concept of security guarantees.
Addressing leaders at the start of the gathering, President Zelensky asked NATO members to take a clear decision on whether to admit Ukraine and also reiterated calls for Western fighter jets to protect Ukrainian skies, as well as providing Patriot missile-defence systems.
Noting that the F-16 fighter jets he is seeking are supplied by the United States, he said after the meeting that he had "heard powerful support from many countries", adding: "With help of the United States we will create this coalition."
Last month, US President Joe Biden endorsed training programmes for Ukrainian pilots on F-16s, although they will take months to complete and Western countries have not yet said they will supply the jets.
Until Ukraine had fighter jets, Russia would continue to have air supremacy, Mr Zelensky said, highlighting the importance of having more Patriot air defences in the immediate term.
At the start of the European Political Community summit - grouping the European Union's 27 member states and 20 other nations in Europe - he said he would seek a clear invitation from NATO for Ukraine to join at the alliance's summit in Vilnius in mid-July.
He said later that Ukraine sought future security guarantees if NATO membership was not possible for now, while insisting that the best security guarantee was membership.
French President Emmanuel Macron said Ukraine needed to be given clear and strong security guarantees at the NATO summit in July.
Mr Macron said he was working closely with Germany on the issue.
"We have to give a long-term perspective to Ukraine. It is imperative that the Vilnius summit gives these immediate guarantees," he said.
German Chancellor Olaf Scholz said such guarantees must "be designed in such a way that they give Ukraine the security it needs against the danger of being attacked, that they also stabilise Ukraine at the same time, which of course also means a commitment with regard to the establishment of defence capability on the part of Ukraine".
There have been divisions between NATO members over the speed of Ukraine's accession, with some fearing that a hasty move could bring the alliance closer to direct confrontation with Russia.
Moldovan President Maia Sandu hosted the summit in a 19th century castle just 20km from Ukrainian territory and near the Russian-backed, breakaway Transdniestria region of Moldova.
"We told President Zelenskiy that we will stand with Ukraine for as long as it takes," she told a news conference closing the gathering.
Mr Zelensky also said that Ukraine was working towards holding a summit to discuss parameters for ending the war but had not set a date yet, as Kyiv wanted to bring more countries to the table.
Leaders used the meeting as a symbolic show of support for Ukraine and Moldova while also tackling other issues, including a rise in ethnic tensions in Kosovo and efforts towards lasting peace between Armenia and Azerbaijan.
The summit was a security and organisational challenge for Moldova, an ex-Soviet republic of 2.5 million people that is seeking a path to EU accession while being wary of Russia.
Ms Sandu, a pro-Western leader whose relations with Moscow became severely strained after Russia's full-scale invasion of Ukraine last year, used the summit to push for talks to make Moldova's EU entry as fast as possible.
Like Ukraine, it applied to join the EU last year shortly after the Russian invasion.
Diplomatic sources said a speech from President Macron in Bratislava yesterday in which he called for EU enlargement "as quickly as possible" was a signal that Paris, once hesitant, would back membership talks for Ukraine and Moldova to start at the end of the year.
The European Political Community is the brainchild of French President Emmanuel Macron, who proposed a forum for EU and non-EU leaders to meet twice a year to discuss the pressing challenges of the day.
Additional reporting Tony Connelly
