Sweden is sending out five million pamphlets to residents urging them to prepare for the possibility of war, with instructions on how to stockpile food and even seek shelter during a nuclear attack, as fears grow of a conflict between Russia and NATO.

Since the start of the war in Ukraine, Stockholm has repeatedly urged Swedes to prepare both mentally and logistically for a possible conflict, citing the worsening security situation in its vicinity.

It comes as tensions between Moscow and the West have escalated to new heights after Joe Biden gave Kyiv the green light to blast targets deep inside Russia with US-supplied long-range missiles, which Donald Trump's son has criticised as making sure 'they get WWIII going before my father has a chance to create peace'.

The booklet 'If Crisis or War Comes', sent out by the Swedish Civil Contingencies Agency (MSB), contains information about how to prepare for emergencies such as war, natural disasters, cyber attacks and terrorism.

'An insecure world requires preparedness. The military threat to Sweden has increased and we must prepare for the worst - an armed attack,' its new introduction states. 

In one of the more worrying excerpts, which harks back to advice given by governments during the darkest days of the Cold War, it informs people of the risk of nuclear weapons.

'The global security situation increases the risks that nuclear weapons could be used. In the event of an attack with nuclear, biological or chemical weapons, take cover in the same way as in an air attack,' the pamphlet instructs readers.

'Shelter provides the best protection. After a couple of days, the radiation has decreased significantly,' it advises, adding that people will be warned of attacks over the radio and should go to basements or subways if there is no better option.

Another message, which has been brought forward from the middle of the booklet in the updated version, reads: 'If Sweden is attacked by another country, we will never give up. All information to the effect that resistance is to cease is false.'