BRUSSELS — EU leaders meeting this week will remain locked in talks until they find a solution to Ukraine’s funding crisis, Cyprus said, insisting the issue won’t be kicked to Jan. 1 when it takes over the EU’s legislative agenda.

Cypriot Deputy EU Minister Marilena Raouna told POLITICO on Monday that leaders have “a critical decision to make at the upcoming European Council,” which begins Thursday. Discussions over how to ensure Kyiv does not run out of money by the middle of next year have been “challenging,” she went on, but “there is a readiness by all to stay in Brussels until we are able to have a decision on this issue of financing.”

European officials have repeatedly warned Thursday’s negotiations could take hours, or even days, to produce a result and may run into the weekend despite pressures on leaders’ schedules. The alternative, officials say, is Ukraine running out of money — which will not be allowed to happen.

The EU is working to agree on a plan to use frozen Russian assets to underwrite a €210 billion loan to support Kyiv’s state budget and help repair the damage done by Russia’s full-scale invasion. However, Belgium — which hosts the bulk of the funds — has been joined by Italy, Malta and Bulgaria in raising legal questions over the proposals, which are already opposed on principle by Kremlin-friendly countries Hungary and Slovakia.

“A number of member states have said we need to ensure there is legal certainty; I think safeguards are being put in place in this regard. And that will pave the way, I hope, for a decision,” said Raouna. “I think we need to exhaust all possibilities … We also need to be aware of what message it would send if we don’t reach a decision.”

Talks between ambassadors on the technical framework behind the move were canceled on Sunday and will run late into the night on Monday instead, ahead of a summit of leaders under the auspices of the European Council on Thursday.

Four diplomats told POLITICO they remain convinced the plan is workable and no alternative exists given capitals’ opposition to borrowing the money directly. Despite that, there are growing concerns that failing to consider other options would mean major delays if the assets plan is rejected.

“I think we are on the right path. I am cautiously optimistic that we will be able to deliver at the European Council,” Raouna said.

Cyprus takes over the six-month rotating presidency of the Council of the European Union from the beginning of next year, giving one of the smallest countries in the bloc an influential role overseeing diplomatic talks. Along with Ireland, it is one of two militarily neutral countries to take on the role in 2026.