The EU's executive arm on Wednesday recommended member states open formal membership talks with Ukraine and Moldova, and that they grant candidate status to Georgia.
The announcement was a major show of support for Kyiv as it has pushed its bid to join in the face of Russia's invasion. Ukraine President Zelensky welcomed the decision, describing it as a 'right step' for Ukraine, Europe
The EU's 27 leaders still have to sign off on the decisions at a summit in December.
"Today is a historic day because today the commission recommends that the council opens accession negotiations with Ukraine and with Moldova," European Commission president Ursula von der Leyen said.
The EU chief said Ukraine and Moldova should still complete further reforms before a formal start date could be set.
She said her executive would issue an update on the progress in March 2024.
"Ukraine continues to face tremendous hardship and tragedy provoked by Russia's war of aggression and yet the Ukrainians are deeply reforming their country, even as they are fighting a war that is existential for them," von der Leyen said.
Ukraine launched its bid to become part of the European Union in the days after Moscow's all-out invasion in 2022, and was officially named a candidate to join in June that year.
The commission at the time set Kyiv seven reform benchmarks to complete, including tackling graft and curbing oligarch power, before talks should start.
Von der Leyen said Ukraine had now completed "well over 90 percent of the necessary steps".
Moldova -- which has complained Moscow is seeking to destabilise it -- lodged its bid to join at the same time as Ukraine and was also given reforms to complete.
Georgia failed to win candidate status along with the other two over worries about the direction of its government.
But the commission said it should now be made an official candidate to join on the understanding it implemented other reforms.
Bosnia, which officially became a candidate in December, failed to get a clear backing to start negotiations.
But von der Leyen insisted "we open the door very wide and we invite Bosnia Herzegovina."
"Now to go through this door for that, of course there has to be activity in Bosnia and Herzegovina, results have to be shown, but the door is now opened very wide," she said.
Even if war-torn Ukraine does start talks, it will still only be at the start of a painstaking process of reforms that could last for years -- if not decades -- before it joins the EU.
Turkey began accession talks in 2005, but those are at a dead end. Albania, Montenegro, North Macedonia and Serbia are also stuck in negotiations.