BRUSSELS — European Union leaders on Thursday are set to grant Ukraine candidate status to join the 27-nation bloc, a first step in a long and unpredictable journey toward full membership that could take many years to achieve.

Making the war-torn country a contender now seems to be a done deal after leaders were initially divided on how fast they could move to embrace the war-torn country’s bid that was launched only a few days after Russia launched its invasion on Feb. 24.

According to several EU diplomats who spoke on condition of anonymity before the summit in Brussels, Ukraine will receive the unanimous approval that is required for the launch of discussions.

The EU’s 27 nations have been united in backing Ukraine’s resistance to Russia’s invasion, adopting unprecedented economic sanctions against Moscow. However, leaders were initially divided on how quickly the EU should move to accept Ukraine as a member, with the Netherlands, Sweden and Denmark among the most skeptical.

But Ukraine’s bid got a boost last week when the EU’s executive arm, the European Commission, gave its seal of approval based on Ukraine’s answers to a questionnaire received in April and early May.

Ukraine received another shot in the arm when the leaders of France, Germany, Italy and Romania visited the country and vowed to back its candidacy.

Ukrainian President Volodymyr Zelenskyy said he spoke with a total of 11 EU leaders on Wednesday, following calls with nine the day before, in another indication of how important EU candidacy is for Ukraine. He said the meeting in Brussels will be an “historic session of the European Council.”

EU candidate status doesn’t give an automatic right to join the bloc, though, and doesn’t provide any security guarantees.

For Ukraine, the start of accession discussions will depend on how the war-torn country will be able to meet essential political and economic conditions.

To be admitted, potential newcomers need to demonstrate that they meet standards on democratic principles, and they must absorb about 80,000 pages of rules covering everything from trade and immigration to fertilizers and the rule of law.

To help countries with candidate status, the bloc can provide technical and financial assistance throughout negotiations, but can also decide to revoke the status if the required reforms aren’t implemented.

European officials have said that Ukraine has already implemented about 70% of the EU rules, norms and standards, but has also repeatedly pointed out corruption and the need for deep political and economic reforms.

It’s unlikely that accession talks could start before next year, with the prospect that the war could drag on for a very long time adding to the uncertainty.

“Considerable efforts will be needed, especially in the fight against corruption and the establishment of an effective rule of law,” Belgian Prime minister Alexander De Croo said. “But I am convinced that it is precisely the (post-war) reconstruction of Ukraine that will provide opportunities to take important steps forward.”

Leaders will also debate Thursday a recommendation for the European Commission to grant Moldova — a tiny, non-NATO country that borders Ukraine — EU candidate status. The stalled enlargement process to include Western Balkans countries in the bloc is also on their agenda.