(CNN)Rising Covid-19 cases have put a halt in San Francisco's reopening plans.
The city had been planning to resume reopening on November 3, but Mayor London Breed announced Friday the city would temporarily hit pause.
"We are starting to see a slight uptick in the number of hospitalizations, which puts us in a situation where things could possibly get worse than what they are," Breed said. "As a result of some changes that we've seen in the numbers, what we will have to do as a result is put a pause on some of our reopening efforts that we have planned for next week."
In a press release, city officials said the reopening pause was due to an uptick of cases and hospitalizations in San Francisco that coincides with an increase in cases across the state and nation.
On Friday, the US officially crossed 9 million Covid-19 cases.
"Today is not unexpected with regard to our pause in reopening," said Dr. Grant Colfax, director of the San Francisco Department of Public Health. "As our activity increased, we realize, we know, we expected an increase in infections was likely."
Colfax said the increase is cause for concern.
"We want to pause on increasing the capacity of riskier activities because we do not want the virus to get too far ahead of us," said Colfax.
The pause means that the indoor capacity for businesses will remain at 25%, according to Breed. The city had planned to expand the capacity for some indoor businesses -- like movie theaters, museums and indoor restaurants -- to 50% starting next week. It would have also meant the reopening of things like indoor pools and locker rooms.
"The more we open, the more people are moving around, the more possibility there could be a spread," said Breed. "The last thing we want to do is go backwards."
Breed said the city made some "very conservative choices" around reopening efforts as it remains in the yellow tier, or the least-restrictive of the state's reopening system which represents "minimal" spread of the virus.
City officials also warned residents to take caution on Halloween and Election Day. Breed warned that parties and gatherings can turn into super spreader events.
"It just takes one person who is infected to infect all of the people who attended a party and that's where we're seeing numbers increase," said Breed. "Even though this year will be a sacrifice, the sacrifice is worth it."
"The holidays are upon us and now is not the time to throw caution to the wind," Colfax added.
The US reached 9 million cases just 14 days after it hit the 8 million mark -- the fastest the country has added 1 million new cases since the pandemic began. Meanwhile, multiple states continue reporting their highest daily case counts since the pandemic began, according to data compiled by Johns Hopkins University.
"If states do not react to rising numbers by re-imposing mandates, cumulative deaths could reach 514,000 by (the middle of January)" reported the Institute for Health Metrics and Evaluation at the University of Washington School of Medicine said in its latest forecast.