A new map shows how Vladimir Putin's Russia could target some of the smallest member countries of NATO in his first military actions against the alliance. There are plans to build more than 1,000 concrete bunkers, anti-tank ditches and a range of other defensive measures to protest the 600 miles of border separating the Baltic nations of Latvia, Lithuania and Estonia from Russia, according to the Telegraph.

It's feared the Kremlin would try to overwhelm the geographically much smaller countries as part of a preliminary attack on NATO. Both the Prime Minister Sir Keir Starmer and Prince William have visited the region in recent months to meet British troops taking part in operations alongside international allies. However, there are reportedly concerns a 10-year project to protect the border with a vast array of defensive structures may have come too late and that if peace is achieved in Ukraine, Putin may look to invade elsewhere.

Gabrielius Landsbergis, who served as Lithuania’s foreign minister until November, told the paper: “[Vladimir] Putin is not going to let us wait those 10 years.

“The most dangerous time for the Baltics will be immediately after a ceasefire in Ukraine.”

A map clearly shows how Russia may carry out an invasion of the Baltic countries, all of which were former members of the Soviet Union, just like Ukraine.

Russia also still maintains the territory of Kaliningrad, which is mostly used as a naval station, and which sits between Lithuania and Poland.

A narrow strip of land, called the Suwalki Gap, separates Kaliningrad from the Putin-backing country of Belarus, and it's feared if Russia did invade, it may try to send forces into the gap to establish a link between Kaliningrad and the Moscow-friendly nation of Belarus.

This could potentially isolate the Baltic states from larger European NATO neighbours, such as Poland.

It's reported Estonia, Latvia and Lithuania will each spend £60 million of their defence budgets towards the scheme. The three tiny nations spend more of their GDP on defence in relation to their size than any other other NATO country, except Poland.

Mr Landsbergis said NATO had effectively asked, “How much are you doing yourself before you ask for our help? When will you start digging trenches and mining your border?”

He added: “We are there now. We are sending a message. I hope that we use every minute that the Ukrainians are giving us in order to prepare.”