The death toll has passed 100 people, and is rising, with some of the worst damage caused by inland flooding in North Carolina.
SEE ALSO: Hurricane Helene leaves nearly 100 dead and a 500-mile path of destruction
In addition to being humanitarian crises, natural disasters can create political tests for elected officials, particularly in the closing weeks of a presidential campaign.
At the beginning of a rally in Las Vegas on Sunday, Harris said "we will stand with these communities for as long as it takes to make sure that they are able to recover and rebuild."
RELATED: 3 active storms in the Atlantic being monitored, with more development expected
Tropical outlook: A tropical storm and another hurricane out in Atlantic Ocean are being monitored
"We're not leaving until the job is done," President Joe Biden said in public remarks about his administration's response to Hurricane Helene on Monday morning. He said he plans to visit areas affected by the storm, with efforts to not disrupt response efforts.
Trump, speaking in Erie, Pa., on Sunday, described the storm as "a big monster hurricane" that had "hit a lot harder than anyone even thought possible."
RELATED: Hurricane Helene: Climate change is making Florida's Big Bend more vulnerable to tropical threats
He criticized Harris for attending weekend "fundraising events with her radical left lunatic donors" in California while the storm hit.
"She ought to be down in the area where she should be," Trump said.
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Trump campaign officials have long pointed to his visit to East Palestine, Ohio, the site of a toxic trail derailment, as a turning point in the early days of the presidential race when he was struggling to establish his footing as a candidate. They believed his warm welcome by residents frustrated by the federal government's response helped remind voters why they had been drawn to him years earlier.
During Trump's term as president, he visited numerous disaster zones, including the aftermaths of hurricanes, tornados and shootings. But the trips sometimes elicited controversy such as when he tossed paper towels to cheering residents in Puerto Rico in 2017 in the wake of Hurricane Maria.
The White House said Harris would visit impacted areas "as soon as it is possible without disrupting emergency response operations." She also spoke with Gov. Roy Cooper of North Carolina, and she received a briefing from Federal Emergency Management Agency Administrator Deanne Criswell while she was traveling.
Associated Press writer Jill Colvin contributed to this report.