Soon after Obama spoke, his administration announced the regional Environmental Protection Agency boss for Flint was resigning amid scrutiny of the agency's role in the lead contamination crisis.
It pointed toward a scaled-up federal response to the crisis, which has caused widespread fury in the poverty-stricken, largely African-American city and beyond.
Obama said $80 million in new funding would be available to Michigan next week for bolstering its cities' water infrastructures.
The new funding was included in the bipartisan budget agreement that was passed last month.
"Our children should not have to be worried about the water they're drinking in American cities. That's not something that we should accept," he said during remarks to a group of mayors who were attending a reception at the White House.
Obama met with Flint's mayor, Karen Weaver, at the White House on Tuesday. She conveyed personal stories from her city, where residents have been told their water contains dangerous levels of lead.
Michigan has been pressing for higher levels of government support, even after Obama signed an emergency declaration for the Flint crisis over the weekend. White House officials have said the more serious designation of a "disaster" is reserved only for natural occurrences like hurricanes.
The crisis has set off a political scandal in Michigan, with accusations the state's Republican governor, Rick Snyder, was negligent in his handling of the crisis.
But Obama's Environmental Protection Agency has also come under scrutiny for not alerting the citizens of Flint that testing had shown unsafe levels of lead in their water supply.
The White House said Thursday that Obama had spoken to EPA Administrator Gina McCarthy this week over the telephone to discuss the agency's process, and to insure its staff aren't impeded from delivering warnings about potentially hazardous environmental conditions.
Late Thursday, the EPA said Susan Hedman, the administrator for EPA's Region 5, had offered her resignation "effective February 1," which McCarthy accepted.
Without detailing the reasons for Hedman's departure, the EPA said McCarthy was intent on ensuring the regional office's "focus remains solely on the restoration of Flint's drinking water."
But the agency continued to point fingers at state and local handling of the crisis, which it said had been "inadequate to protect public health."
"There are serious, ongoing concerns with delays, lack of adequate transparency, and capacity to safely manage the drinking water system," a statement from the agency read.