Ben Wallace met his Danish and Swedish counterparts in Copenhagen to mark the start of activity by the Joint Expeditionary Force, a UK-led coalition of ten northern European states focused on security in the Arctic, Baltic and North Atlantic.

Following Russia's invasion of Ukraine on 24 February, the Joint Expeditionary Force announced "an exercise demonstrating JEF nations' freedom of movement" in the strategic zone.

We are "worried if a new Cold War and a new Iron Curtain will descend across Europe," Wallace said, speaking on the deck of the Danish frigate Niels Juel.

Under a Swedish escort, the ship will deliver Danish troops to bolster NATO deployments in Estonia, Wallace said.

He said the moves sent a message to President Putin "that we are all together, whether in NATO or not, joined at the hip by our common values".

Danish defence minister Morten Bodskov warned of the "horrific situation" in Ukraine and called on the international community "to send a strong and clear signal that what we're seeing now is completely unacceptable".

The JEF, set up in 2012, is made up of NATO members Denmark, Estonia, Iceland, Latvia, Lithuania, the Netherlands, Norway, and the United Kingdom, and non-members Finland and Sweden.

"The one thing we all know President Putin doesn't like is seeing lots of international flags," Wallace said.

"When he sees Sweden, Finland, NATO countries side by side that's the strongest message we can send."