Harris will travel to Raleigh, in North Carolina, a state Democrats remain hopeful they can flip this election, to outline a plan "to lower costs for middle-class families and take on corporate price-gouging," a campaign official said.
Plans for the event have not previously been reported. Harris canceled an event in North Carolina last week because of Tropical Storm Debby.
Harris' North Carolina stop shows increasing confidence in her campaign's momentum fewer than three months before the Nov. 5 election in which she takes on Republican Donald Trump.
While the campaign sees states like Pennsylvania as must-win, North Carolina is more of a reach. Democrats have only won two presidential elections there in the last half-century.
Harris' speech will be closely watched to see how the style or substance differs from that of U.S. President Joe Biden, whose economic policies received low marks from voters angry about the cost of housing, medicine, groceries and gasoline.
On Saturday, Harris announced her support for eliminating taxes on tips, a position similar to Trump's. Harris will hold a White House event with Biden on Thursday that is expected to focus on healthcare costs.
Harris policed "corporate greed and price gouging" when she was California's attorney general from 2011 through 2016, challenging pharmaceutical, oil, electronics and cosmetics companies, the campaign official said.
Harris "knows costs are too high and will make tackling inflation a 'Day One' priority," added the official who declined to be identified speaking about the event beforehand.
The approach marks a striking difference from Trump, who has argued that loosening regulations on industries from finance to energy will lower costs and spur growth.
Nationally, Harris was ahead of Trump by five percentage points, 42% to 37%, in an Ipsos poll published on Thursday, widening her lead from a July 22-23 Reuters/Ipsos survey.
