"You can't rule anything out in this crisis and the prime minister has said that from day one," the justice secretary says.
A minister has admitted England's coronavirus lockdown could be extended beyond 2 December.
"We've got to follow the evidence," Justice Secretary Robert Buckland told Kay Burley.
"If there isn't to be an extension of this we go back into the tier system anyway, so we'd leave on a regional or local basis.
"You can't rule anything out in this crisis and the prime minister has said that from day one."
Pubs, bars, restaurants and non-essential shops are now closed for a four-week period in a bid to control the spread of COVID-19.
People will also be told to stay at home except for when attending school, college, university or work, or going food shopping.
Prime Minister Boris Johnson has set out his determination for the lockdown to end after four weeks, describing the restrictions as "time limited".