Lightfoot previously said Chicago is forecast to have a $1.2 billion budget gap for 2021, reflecting the impact of the COVID-19 pandemic.
She has hinted at job cuts in order to fill the deficit, a mix of furloughs and layoffs.
"Make no mistake. This will be our pandemic budget," she said. "In this dire circumstance, where there are nothing but painful choices, everything has to be on the table."
The 2020 shortfall has grown to nearly $800 million, the mayor said.
In August, Lightfoot said that deficit would be filled using relief funds and other federal aid. She thinks how the city gets through the fiscal crisis could be a topic of debate Wednesday night between Vice President Mike pence and his challenger Sen. Kamala Harris, saying Pence might have trouble defending President Donald Trump's leadership during the pandemic.
Lightfoot delayed laying out her budget plan until Oct. 21 in the hopes Congress would have more time to come up with a stimulus funding plan.
But after Wednesday's council meeting, she said she did not think the federal government would come through with aid in time.
"I think there were many opportunities to get this done, but I think with the president's tweet midday, saying 'stop negotiating,' I don't believe that it's gonna happen," Lightfoot said.
Lightfoot previously said revenue loss from COVID-19 accounts for 65% of the city's budget gap, with tax receipts plummeting from lack of tourism, as well as restaurant, hotel and convention businesses.
The mayor also added that budgeting for public safety next year will mean funding for both the Chicago Police Department and community support structures.
The mayor said she'll take a hard look at police overtime and other aspects of the CPD budget, but said defunding the police is not the answer.
In order to bring in revenue, Lightfoot called for the need for a casino surrounded by a "world class entertainment district."
With city resources and services at risk, the mayor has previously promised to use a TIF surplus and consider a computer lease tax as other potential measures. She would not say what might happen to property taxes.
During Wednesday's council meeting, an ordinance was approved that updates city forms, paperwork and templates to include gender-neutral and gender-affirming language options.
The council also remembered public figures who have recently died during Wednesday's meeting.