The UK is telling families to prepare three days' worth of food, water, and essentials amid concern that natural disasters, armed conflict, and other emergencies are becoming more frequent.

UK Prime Minister Andy Burnham's office launched the "Be Ready" campaign last week, urging British people to arrange household stockpiles including the following items:

• Three days of non-perishable food, such as dried fruit or tinned meat
• Nine liters of bottled water, or about 2.4 gallons, per person
• Hygiene and bathroom products, including wet wipes and hand sanitizer
• Warm clothing, sleeping bags, and blankets
• Light sources, such as flashlights with batteries
• A charged power bank
• An FM radio
• Cash and cards, copies of identification documents, and important information such as a note of personal medical dosages
• A first aid kit and other essential medical supplies
• Ready-made baby formula and diapers
• Pet food and bottled water

The idea is to give households the ability to hold out for three days while cut off from supplies or payment systems.

Burnham said the campaign was started as "unexpected events seem to be becoming more and more common," but urged people not to panic.

"It's about just taking sensible measures to have enough in the house to tide you over should there be a difficult situation," he told local media on Friday.

The campaign encourages people to build their stockpiles gradually, for example by adding some items to regular shopping trips, and to check them every six months to replace any that have expired.

It comes as government agencies and companies around the world temporarily shut down their websites last week after a major security flaw was found in an open-source programming language that powers about 70% of the internet.

"We're going to find these sorts of things happening more and more," said the UK's defense minister, Wes Streeting, on Friday. "And it's not just from foreign states engaging in espionage or sabotage. It's also organized criminals."

About 400,000 British homes also lost power at some point over the weekend as two back-to-back storms battered northern Europe.

But UK officials have also increasingly warned about the need to deter the threat of war in Europe, and are hoping to raise their country's national resilience in the face of such a possibility.

"Our adversaries' willingness to harm us is not new. What has changed is their capacity. By 2030, their force strength and war economy could put them in a position to attack," Streeting told The Telegraph on Sunday.

The defense minister added that the UK had 1,000 days left to prepare itself for war.