"Today marks a crucial step on your path towards the EU," European Council President Charles Michel said on Twitter after talks in Brussels. Leaders also agreed to approve Moldova's candidacy.
Ukraine's President Volodymyr Zelensky said he "sincerely commends" the European Council's decision, calling it "a unique and historical moment in EU/Ukraine relations."
The decision, made at an EU Council summit, comes a week after President of the European Commission Ursula von Der Leyen said it was the opinion of the bloc's executive body that Ukraine deserved candidate status because it "has clearly demonstrated the country's aspiration and the country's determination to live up to European values and standards."
However, it is still likely to be years before Ukraine is able to join the EU. The process is lengthy and requires agreement from the 27 member states at almost every stage. This means that there are multiple opportunities for member states to use their veto as a political bargaining chip.
Before Ukraine can start negotiations to join the bloc, it must first meet the Copenhagen criteria -- an opaque trio of requirements that focus on whether or not a country has a functioning free-market economy; whether its institutions are fit to uphold European values such as human rights and the EU's interpretation of the rule of law; and whether it has a functioning, inclusive democracy.
It is unlikely that Ukraine will be able to meet these criteria while the country is at war, however, von der Leyen acknowledged that it had started making progress on reaching them long before the invasion.
Once these criteria are met and all member states have agreed to start talks on the 35 negotiating chapters -- ranging from trade to law to civil society -- Ukraine must then make domestic reforms in order to meet the required standards in each of these areas. Again, all member states must agree that these requirements have been met before closing each chapter.
Once that has happened, the European Parliament and legislative agendas must approve the decision and, finally, Ukraine will be an EU member state.
The average time it takes to join the EU is four years and 10 months, according to the think tank UK in a Changing Europe. However, some member states in eastern Europe have had to wait as long as 10 years.
On top of a lengthy and complicated process, there are also political considerations that could thwart Ukraine's European dream.
Not every member state is thrilled about Ukraine being considered for accession to the bloc. Therefore, it is likely that at every stage one or more will be tempted to throw a spanner in the works in order to get a concession on something else that the EU is debating -- such as allocation of EU money.
France and Germany and Hungary have been less than full-throated in their support. It was only after a visit to the Ukrainian capital, Kyiv, that the leaders of France, Germany and Italy indicated that they would support Ukraine's candidate status. Hungary has also dragged its feet, for various reasons, though most notably because it is Russia's biggest ally in the EU.
Some European countries have also been criticized by Zelensky for not providing enough weapons as Ukraine is in the midst of a desperate battle to defend the Luhansk region in the east of the country.
The reasons for their hesitance range from concerns about corruption to a shift in power from the west of the bloc to the east if Ukraine is admitted. There are also concerns about how much of the EU budget Ukraine might eat up.
While all member states have supported the candidacy, there are still multiple opportunities for leaders to dig in their heels over the coming years.
Ukraine's long journey to the EU has only just begun. Its candidate status might present a moral victory and send a loud message to Russia. But the reality is, Ukraine must now -- pretty much on its own -- make reforms that would be hard enough at the best of times, let alone while under invasion from a foreign army.