"If there's no mask, there should be no service,'' Garcetti said.
Gov. Gavin Newsom on June 18 ordered everyone to wear masks or face coverings while in public or "high-risk situations,'' but people have been seen disobeying those orders frequently in Los Angeles.
There's also no enforcement of the mask order by the Los Angeles Police Department, as Garcetti said he hopes to encourage people to comply rather than issue citations.
Garcetti's comments during his COVID-19 update came on the same day Newsom ordered restaurants to stop indoor dining service and the closure of museums, zoos, aquariums and card rooms for three weeks in certain counties, including Los Angeles, due to the rapidly rising number of cases.
RELATED: Los Angeles COVID-19 update: Health officials confirm over 2,000 cases for fourth day in a row
Despite the order to stop indoor dining services, Garcetti said restaurants are still able to provide outdoor dining through the L.A. Al Fresco program, and he said about 560 businesses have received permits to expand dining in parking lots and on closed streets.
Throughout the pandemic and Garcetti's "Safer at Home" orders, restaurants have been allowed to provide takeout or delivery service.
Garcetti said Wednesday Los Angeles began sending out volunteer disaster service workers to check on businesses that are allowed to remain open to ensure they are following the county's COVID-19 health and safety guidelines.
Garcetti said researchers have gathered more information on the virus since it struck the United States, "but in recent days, the trend is clear: cases are on the rise.''
"To be clear, everything we do is not going to make things better. I want to be straight with everybody,'' Garcetti said. "Anything we do today, we won't see the benefits for two to three weeks. That's how this disease works.''
Newsom's order Wednesday impacts 19 counties that represent more than 70% of the state's population and include several counties in Southern California. Los Angeles, Orange, Riverside, San Bernardino and Ventura are all on the list of those impacted by the mandate.
RELATED: Gov. Newsom orders indoor restaurants, wineries, movie theaters to close in most of CA
The trends in California that prompted the order have only gotten worse. Nearly 6,000 people tested positive for COVID-19 over the past 24 hours. That brings the positivity rate, or the proportion of people tested for COVID-19 that end up positive, to a 6% average over the past two weeks. It was 4.6% two weeks ago.
"That's a very high increase. It may not seem like much to some but every decimal point is profoundly impactful," Newsom said.
Hospitalizations have climbed 51% over the past two weeks and ICU admissions are up 47%.
As of Wednesday an additional 110 people lost their lives to the virus over a 24-hour period, the governor said.
Meanwhile, Los Angeles' color-coded system to indicate the threat level of COVID-19 was indicated as "Orange'' on Wednesday, which means there was an "extremely high risk of infection and residents should take precautions and assume you and everyone around you is infectious,'' according to the website corona-virus.la/covid-19-threat-level.
RELATED: LA launching new color-coded threat level system to warn of coronavirus danger
The system ranges from green, which means the virus has been all but eliminated, to red, which means people can only go outside for essential goods and travel to work, but they must stay at home all other times. Red also means hospitals are being overrun with COVID-19 cases.
Garcetti said he will start sending mobile coronavirus testing teams to factories in Central and South Los Angeles after coronavirus outbreaks were reported. The mobile testing teams were first dispatched to skilled nursing facilities that were hit hard by COVID-19 in the spring.
"(Factory) workers can unknowingly take their virus home with them in dense residential areas, which poses a threat to all the people who live with them and their neighbors, especially those who are older or who have underlying health risks,'' Garcetti said.
RELATED: Not wearing a mask in West Hollywood could cost you $300
Garcetti said in these factories, social distancing is hard to do because most of the employees work in close quarters.
Beaches, piers and beach bike paths in the city and county of Los Angeles will be closed from Friday to Monday to discourage gatherings over the Fourth of July Weekend.
"This Fourth of July weekend, please wear face coverings and avoid gatherings,'' Garcetti said. "This is a critical time in our fight against COVID-19.''
City News Service contributed to this report.