The plea has been issued by David Hall, chairman of Northumberland Tourism, ahead of the easing of coronavirus restrictions.
He said: “Following the Government’s revised guidance, we are working closely with local and national partners on our plans for the future.
“Whilst we welcome the Government's move towards recovery, the pandemic is far from over, and we need to understand what the revised guidelines mean for Northumberland and the tourism industry.
“We have a responsibility to make sure that Northumberland is a safe place to live, work and visit, and until the virus is under control, we ask visitors to stay away to protect our communities.
“We stand poised and ready to promote our world-class destination when the time is right, when our businesses are safe and ready to reopen, and when we can start to welcome people back to our beautiful county and enjoy everything it has to offer.
“For now however, we ask everyone to act responsibly, to respect the virus, and return only when it's safe to do so.”
From Wednesday May 13, people will be allowed to ‘travel to outdoor open space irrespective of distance’ and take ‘day trips to outdoor open space’ while observing social distancing rules.
A statement from the Northumberland National Park Authority on Monday, said: ‘Following the Prime Minister’s address to the nation on Sunday, May 10 , Northumberland National Park Authority expects that more people will be preparing to access the countryside as of Wednesday.
‘We are digesting what the statement means for the National Park and looking at how we can safely prepare for this. We will releasing an updated statement and further details as soon as we can.
‘In the meantime, people are still encouraged to avoid unnecessary travel to the National Park.’