Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

FLINT, Michigan — Democratic presidential candidate Hillary Clinton called for "action now" to combat the toxic water crisis here Sunday in a speech to a packed congregation.

"This has to be a national priority," Clinton said at the House of Prayer Missionary Baptist Church. "What happened in Flint is immoral. The children of Flint are just as precious as the children of any part of America."

Clinton, who took a detour from campaigning in New Hampshire to visit the ailing city, said clean water is a basic right that is "not optional, my friends." She called on Congress to pass a $200 million bill to replace Flint’s current water infrastructure.

Aside from her speech at the church, Clinton met with residents and toured neighborhoods with Mayor Karen Weaver. Both women received long standing ovations when they entered the church.

Related: Sanders, Clinton Call for Federal Rescue in Flint

Clinton started her remarks the way she often does in a house of worship, with a psalm: "This is the day that the Lord has made. Let us rejoice and be glad in it," she said, quoting Psalm 118:24.

Clinton praised Mayor Weaver as "someone who is working every way she knows how to provide the help and support that all the people of Flint deserve to have."

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

The Democratic front-runner said would have preferred to come to Flint for a different reason. "I wish I were here only to celebrate the good things that are happening in this church and in this community," she said.

Hillary Clinton at the House of Prayer Missionary Baptist Church in Flint, Michican, on Sunday, February 7. Monica Alba

Clinton told the congregation about her meeting with several young mothers whose children are suffering from lead poisoning. "I was just heartsick," she said after their conversation.

The former secretary of state started speaking out on the Flint water crisis several weeks ago, releasing statements and calling it a “civil rights issue" on the campaign trail.

"I was so angry. I was outraged and I know you must feel exactly the same," she said. "Repairing trust is as important as repairing pipes."

At the NBC News debate in Charleston last month, Clinton argued that if something similar had had happened in a wealthy suburb of Detroit, there would be a solution by now. She reiterated the sentiment Sunday.

Related: Feds, State Blame Each Other for Flint Water Crisis

"This is not time for politics as usual," she said. "I will fight for you in Flint no matter how long it takes."

The DNC has sanctioned an additional debate here on March 6, two days before the Michigan primary.

At the church, Clinton spoke in front of a mural of John the Baptist lowering Jesus into a pool of water.

"No matter how bad the water is, life is still worth living," Pastor Kenneth Stewart said before introducing Clinton. "God is just reminding Flint that: 'I didn’t forget you.'"

"We just can’t give up. We can’t give up now," the congregation sang, swaying together. "We’ve come too far from where we started from."

At the end of her speech, Clinton promised to come back to Flint and encouraged the community not to get discouraged.

Storyline: Flint Water Crisis

"Do not give up. The road is long and I know that there will be a lot of bumps along its way but this is the most important work we are ever called to do: to reach out in every way we can, no matter who we are, to lend that helping hand," she said.