The 27 leaders of the European Union decided on Thursday to begin accession negotiations with Ukraine and Moldova.
ADVERTISEMENTThe bloc also granted Georgia the status of candidate country, having previously been denied such title.
"A clear signal of hope for their people and for our continent," said Charles Michel, the president of the European Council.
Additionally, the EU "will open negotiations with Bosnia and Herzegovina once the necessary degree of compliance with the membership criteria is reached."
The European Commission will have to report by March on the progress made by the Balkan country in order to decide the next steps.
Thursday's breakthrough, achieved during a summit of leaders in Brussels, came amid Hungarian Prime Minister Viktor Orbán's veto threats and antagonistic rhetoric.
In the days leading up to the meeting, Orbán has questioned Ukraine's readiness to start negotiations and the Commission's credibility as an impartial arbiter.
"Enlargement is not a theoretical issue, it's a merits-based, legally detailed process, which has preconditions," the premier said upon arrival on Thursday. "If you haven't fulfilled the preconditions, there is no chance to start the negotiations."
"We have to come back later on and revert to that issue again when it is fulfilled by the Ukrainians," he added.
It was not immediately clear what made Orbán lift its veto.
After settling the matter of enlargement, EU leaders will now dive deep into the negotiations about the revision of the bloc's common budget, which includes a €50-billion special fund to provide Ukraine with long-term financial support.
Orbán has equally threatened to derail the fund.
This is a developing story.