Merz spoke on December 16, 2025, in an interview with ZDF, one day after talks in Berlin involving Ukrainian President Volodymyr Zelenskyy, U.S. envoys, and European leaders.

Those discussions followed a December 15 joint European statement endorsing a U.S.-led peace initiative under President Donald Trump, contingent on a ceasefire.

A Demilitarized Zone, Enforced

Merz described a framework in which a demilitarized zone would separate Ukrainian and Russian forces after a ceasefire, with multinational guarantors responsible for its security. 

“The guarantors would need to repel Russian forces should there be a violation of any ceasefire terms,” he said, a formulation reported consistently by Reuters, The Guardian, and others. 

He added that peacekeepers would not be passive observers: 

“We would secure a demilitarized zone between the warring parties and, to be very specific, we would also act against corresponding Russian incursions and attacks.”

European-Led, U.S. Backed

Under the proposal discussed on December 15, the force would be primarily European-led, with U.S. support but no U.S. ground troops deployed inside Ukraine. 

European leaders including Merz, French President Emmanuel Macron, and British Prime Minister Keir Starmer backed the concept of a “multinational force” tasked with supporting Ukraine’s security, including force regeneration, air defense, and maritime security. 

Merz said U.S. commitments would treat a post-ceasefire Ukraine “as if it were NATO territory” for protection purposes, underscoring the depth of the proposed guarantees.

Conditions and Constraints

Merz stressed that the idea remains hypothetical. 

“We’re not there yet,” he said, emphasizing that no ceasefire has been agreed and that any deployment depends on Russian consent to both a halt in fighting and the presence of Western forces. 

As of December 17, 2025, Russia has not accepted a ceasefire, Western troops on Ukrainian soil, or the broader security framework outlined by Washington and European capitals.

Escalation Risks, Acknowledged

Pro-Russian commentators have framed Merz’s remarks as an admission that the plan could lead to direct clashes between Western and Russian forces if violations occur. 

Western officials counter that the clarity of enforcement is intended as deterrence, not provocation, by defining consequences in advance.