The European Union is on the precipice of a momentous decision on whether to use frozen Russian assets to finance more support for Ukraine. Critics argue the plan is legally questionable and risks retaliation by Moscow.

The European Commission has proposed that the leaders use some of the frozen assets — totaling 210 billion euros ($246 billion) — to underwrite a 90 billion-euro ($105 billion) “reparations loan” to Ukraine. The U.K., Canada and Norway would fill the gap.

The European Union wants to impose strict “Buy European” rules on Ukraine’s potential loan backed by Russian assets, which leaders will try to finalize during a summit on Thursday.

The Kremlin said on Wednesday that Russia's position on the deployment of any European troops to Ukraine under a possible future U.S.-brokered peace deal was widely known but that the subject could be discussed.

Often left out by the United States in peace negotiations, European countries are working to assert their leadership and bolster Ukraine with an ambitious funding plan. But can they agree?

Germany is undergoing a significant military rearmament. The change has been driven by the ongoing war in Ukraine and U.S. pressure on Europe to shoulder more of its defense.

European leaders said they had agreed on Monday any decisions on potential Ukrainian territorial concessions to Russia could only be made once robust security guarantees were in place which should include a European-led multinational force.

The latest proposal is designed to deter future Russian aggression. But Russia is not part of the talks and has shown little willingness to negotiate.