Captain Sir Tom Moore has launched a new campaign to get people walking to help support those who feel "lonely and frightened" during lockdown.
The veteran raised £33m for the NHS by walking 100 laps of his Bedfordshire garden before his 100th birthday.
Capt Sir Tom said: "We are in a difficult situation but we'll get through it if we all join together."
The challenge encourages people to log their walking on social media using the hashtag #WalkWithTom over the next week.
Capt Sir Tom hopes to raise money for his foundation, which aims to combat loneliness and support those facing bereavement.
The 100-year-old, who was born in Keighley, West Yorkshire, said he has "always been optimistic things will improve".
He said the second England-wide lockdown would be difficult but "we will get through it".
Inspired by Capt Sir Tom
Capt Sir Tom said: "We've got to consider that during this next coming period there are going to be a lot of unhappy people who are lonely and frightened and we need to go out and help those people.
"That's why we've got the Captain Tom Foundation."
Set up in September, it works with four charities, the mental health charity Mind, The Royal British Legion, Helen and Douglas House children's hospice in Oxfordshire, and Willen Hospice in Milton Keynes.
Capt Sir Tom's daughter Hannah Ingram-Moore said the family had been "given an incredible gift of a voice and platform to do powerfully positive things with".
She said they wanted to "remind people that we are British and we can get through this".
"We would like everyone to walk together with Tom so we can help support those who are lonely," she added.