European leaders, primarily France and the United Kingdom, have advanced planning for a multinational reassurance force through a Coalition of the Willing, including signed letters of intent and headquarters coordination, but any deployment remains conditioned on a prior ceasefire with Russia. As of mid-September 2026, active hostilities continue without an agreement, and Russian President Vladimir Putin has warned that introducing such troops would constitute an act of war. Recent U.S.-mediated diplomatic efforts, including envoy visits and proposed trilateral talks potentially in October, alongside a planned Trump-Zelenskyy meeting, represent key near-term catalysts that could shift prospects for a formal announcement by an EU or NATO member by year-end. Trader consensus reflects caution tied to the absence of resolved security guarantees or peace framework.