Efforts to establish a multinational reassurance force for Ukraine are progressing, with defence ministers from 30 countries meeting in Brussels on Thursday to refine operational plans. However, questions about troop contributions, timelines and the specific role of the force remain unresolved, particularly amid concerns about the absence of U.S. participation.

The high-level meeting, held under the “Coalition of the Willing” initiative and co-led by the UK and France, took place at NATO headquarters. The primary goal is to form a post-peace deal security presence in Ukraine that can deter any renewed aggression from Russia and support long-term stability in the region.

Plans Move Forward Amid Caution

UK Defence Secretary John Healey, speaking at the opening of the session, emphasised the coalition's readiness and objectives: “Our planning is real and substantial. Our plans are well developed and we have clear objectives for Ukraine.” He explained that the session focused on the coalition’s operational planning and ensuring preparedness when a peace deal is eventually reached. “We cannot jeopardise the peace by forgetting about the war and the daily reality for millions of Ukrainians,” Healey warned.

The meeting follows recent visits to Kyiv by senior French and British military leaders, who met with Ukrainian President Volodymyr Zelenskyy, Defence Minister Rustem Umerov, and other top military officials. These visits aimed to discuss deployment logistics and identify suitable strategic locations where the force might be stationed.

French President Emmanuel Macron, who convened a summit of leaders on this issue in March, previously stated that the reassurance force could be stationed in key Ukrainian cities. He added that contributions would extend beyond combat troops and could include logistics, intelligence sharing, and other non-combat roles.

However, not all the 33 delegations present at Macron’s March summit agreed to contribute troops. Nations such as Poland and Greece have opted out of providing personnel, citing their own security priorities—Belarus and Turkey, respectively—as significant threats requiring a domestic military focus.

Troop Commitments Still Unclear

Defence ministers remained cautious about specifying how many troops could be deployed or setting any concrete timeline. Andris Sprūds, Latvia’s Defence Minister, acknowledged the progress made but noted that the final scale of involvement will depend on the terms of any future peace agreement. He said Latvia does not rule out contributing troops, as long as its own defence posture on the Russian border remains intact.

“There is a sense of urgency,” Sprūds added, but emphasised that clarity on the force’s purpose—whether it is deterrence, peacekeeping, or monitoring—is needed before countries commit further.

EU foreign policy chief Kaja Kalals echoed these concerns. “The goal of the reassurance force—whether it is deterrence, monitoring, or peacekeeping—must be clearly defined,” she said, underlining the importance of agreement on the mission's scope before moving forward.

Uncertainty Over US Role

One major sticking point remains the role of the United States. Several countries have made it clear that their full commitment depends on some level of American involvement, particularly in providing air cover, intelligence capabilities, and logistical support.

Finnish Defence Minister Antti Häkkänen called the U.S. a “crucial player that must be involved somehow,” a view echoed by Dutch Defence Minister Ruben Brekelmans, who added, “Of course, it is good if the US is very explicit about its support and backstop… it really depends on the mission to what extent US involvement is needed.”

So far, Washington has not committed to joining the coalition. Despite ongoing talks between President Emmanuel Macron, British Prime Minister Keir Starmer, and U.S. President Donald Trump, the American stance remains cautious. Trump has been kept updated on developments, but the U.S. has not agreed to participate formally.

Adding to concerns, the U.S. has stepped back from the Ukraine Defence Contact Group—commonly known as the Ramstein group—which it previously led under the Biden administration. U.S. Defence Secretary Pete Hegseth is not expected to attend the group’s upcoming meeting, which is set to include representatives from around 50 countries.

Progress Made, But Key Questions Remain

While Thursday’s meeting at NATO headquarters showcased significant progress in establishing a reassurance force for Ukraine, numerous challenges remain. The coalition’s framework is taking shape, but important decisions regarding the mission’s purpose, troop levels, timelines, and most critically, U.S. involvement, are still pending.

As the war in Ukraine grinds on and peace negotiations remain distant, the “Coalition of the Willing” continues to walk a delicate line—pushing forward with preparations while grappling with deep strategic concerns and political realities. The coming weeks will be pivotal in determining whether this force can become a credible and unified security guarantee for post-war Ukraine.