BRUSSELS, Dec. 15 (Xinhua) -- The European Union's discussions on financing future support for Ukraine, including a plan to leverage frozen Russian state assets, have become "increasingly difficult," said an EU official on Monday.

EU High Representative for Foreign Affairs and Security Policy Kaja Kallas made the remarks ahead of the EU's Foreign Affairs Council session in Brussels, noting that EU leaders are due to meet on Thursday and Friday for the last summit of the year.

The bloc is working toward a decision on Ukraine's funding at the gathering. "We will not leave the meeting before we get a result," she said.

Several financing options remain on the table, but the "most credible option" is a so-called "reparations loan" backed by frozen Russian assets, Kallas added.

The financing push comes as the EU seeks to stabilize support for Ukraine into 2026 and 2027.

Western countries have frozen roughly 300 billion U.S. dollars in Russian sovereign assets since the start of the Russia-Ukraine conflict in February 2022. The European Union has immobilized about 210 billion euros (about 246.4 billion dollars) of Russian central bank assets, most of it held at Belgium-based Euroclear in Brussels.

Earlier this month, EU governments agreed to indefinitely immobilize those Russian central bank assets, a shift from the previous system of rolling renewals every six months, to reduce the risk that a single member state could block the measure.

Belgium, which holds the bulk of the immobilized assets, has raised legal and financial liability concerns about the "reparations loan." Those concerns have complicated previous efforts to reach a deal on the proposed loan. Enditem