Britain will fight any plans for a European Union army, Defence Secretary Michael Fallon has said.
Sir Michael joined his fellow defence ministers from across the bloc in the Slovakian capital, Bratislava, to discuss the ambitious project to strengthen military capability across the continent.
He said: "We are going to continue to oppose any idea of an EU army or EU army headquarters.
"Nato must remain the cornerstone of our defence."
However, asked if Britain would veto the move, he said only that "there is no majority here for an EU army".
The proposals could see a new joint EU military command, as well as increased defence spending and joint development of assets such as helicopters and drones.
The move is being spearheaded by France and Germany, who insist the plan is aimed at improving co-operation and not creating the EU's own army.
Sir Michael had previously said Britain would fight any plans by the EU to create any new body that undermined Nato.
While all EU members have their own military force, the majority are also members of Nato.
Britain retains full voting rights in the European Union until it leaves following Brexit.