Sweden and Finland have updated guidance to their citizens on how to survive war, as NATO allies bolster defense measures against the backdrop of the Ukraine conflict.

The two Nordic nations joined NATO after Russia’s invasion of Ukraine. With tensions rising, they are preparing their citizens in the event the threat spreads.

Russia's invasion of Ukraine has alarmed neighboring countries and Sweden's bringing back its guide to surviving war.

Sweden has a long history of producing war-time manuals for its citizens. "If War Comes" was produced in World War Two and updated during the Cold War. One passage has been elevated in the new booklet: "If Sweden is attacked by another country, we will never give up. All information to the effect that resistance is to cease is false."

Sweden and Finland warned citizens about the potential of a war, urging them to be ready, as the Russia-Ukraine war drags toward the end of its

Swedish Civil Defense Minister Carl-Oskar Bohlin tells CNN’s Eleni Giokos the update was made to reflect the country’s dire security situation his country now faces.