The Cabinet has agreed to forbid all non-essential activities from midnight on Sunday.
Making this announcement, the Prime Minister also called on everyone except essential workers to stay at home unless they had to go out.
There will not be a state of emergency, but he said this ban could be enforced under existing legislation.
The measure will be in place until April 15.
Dr Rowley explained this new "deeper separation" during a post-Cabinet press briefing.
He said the ministers of health and national security would provide a list of what counted as "essential activities."
He noted that medical personnel, people in the public utilities and social services were essential.
"The airport and seaport have to stay open because our food has to come in. There is a huge chunk of the country that still has to function as a response to the virus," Dr Rowley said.
"We understand that some people are required to be out and some are required to be in. The food and market sector has to be out there."
He said the Government would identify a large block of the population that is non-essential and they are required to stay at home
"You see the liming and congregating?” The police will enforce the law, with the full support of the defence force,” he warned.
"If you must go to work, to do these things in the essential sector, you would have to make arrangements.
Rowley appealed to all citizens to be responsible, saying this is the only way to save lives.