"When our county health officer Dr. (Barbara) Ferrer merely said that an order would stay in place for at least three more months, that doesn't mean the order stays in place exactly as it is today," Garcetti said on CNN.
The mayor said the city can not fully reopen until a vaccine has been developed.
"It's just a reminder of how delicate and fragile this time is, but do not freak out when you hear a scientist say that it's still going to be here and we're still going to be living under health orders," Garcetti said about the extension.
LA County's stay-at-home order will likely remain in place for next three months, officials say
The mayor talked about the extension during an interview on ABC's Good Morning America on Wednesday.
"I think we all have to recognize that we're not moving beyond COVID-19, we're learning to live with it," Garcetti said. "It's important not to overreact but it's important to take this serious because it's as dangerous today as it was the first day that it arrived in our cities and our country. So quite frankly, there's no so-called 'open state' or 'open country' that doesn't continue to have health orders telling us to cover our faces, physically distance and to tell people that you're safest working from and staying at home. That's all that the country health director was saying."
WATCH: LA Mayor Garcetti says Americans are 'learning to live with' COVID-19
Public Health Director Dr. Barbara Ferrer said the order will "with all certainty" be extended unless there is a "dramatic change to the virus and tools at hand."
Ferrer made the comments at a Board of Supervisors meeting Tuesday during a debate over how long the county's moratorium on evictions should remain in place.
"There's no radical changes in the next week coming but that doesn't mean, three weeks from now, six weeks from now, two months from now we won't continuously edit that order," Garcetti also said on CNN.
Garcetti said the county is testing 20,000 people each day. Meanwhile, COVID-19 cases and deaths continue to rise in the region.
Los Angeles has gradually begun a reopening of certain businesses and recreational areas, and on Wednesday, beaches reopen with restrictions.
Last month, officials extended the county's "safer at home" order until at least May 15. The region's reopening would be based on a four-point plan whose prerequisites would have to be achieved before the easing of restrictions could begin.