() The mayors of four major U.S. sanctuary cities are set to defend their cities’ status in a House Oversight and Government Reform Committee hearing Wednesday.

Boston’s Michelle Wu, Chicago’s Brandon Johnson, Denver’s Mike Johnston and New York City’s Eric Adams will face questions from Republicans, including committee chairman James Comer, who has vowed to hold the mayors accountable for their policies.

In January, Comer launched an investigation into sanctuary city practices he claims put “Americans’ lives at risk.”

The hearing is slated to begin at 10 a.m. ET and is available to stream on the House’s official website.

What is a sanctuary city?

While there’s no set definition of a sanctuary city, the term generally refers to cities that limit cooperation with Immigration and Customs Enforcement.

President Donald Trump’s border czar, Tom Homan, says a rise in modern transnational criminal gangs has created an unprecedented risk one he’s vowed to “eradicate.”

“This is the biggest national security issue this country has seen, and we’re going to address it,” Homan said in reference to Tren de Aragua and MS-13.

Supporters of sanctuary cities say they want to be welcoming landing spots for immigrants.

“That’s just who we are. We’re a city, again, that was established by a black Haitian immigrant. That is the punch. We’re responding to individuals who don’t share our values,” Chicago’s Johnson said.

They also warn that victims and witnesses of crimes who are in the country illegally may be less likely to come forward if local law enforcement is cooperating with ICE.

The only one of the four mayors who seems willing to join forces with the Trump administration’s effort is New York’s embattled Adams, who has voiced support for rolling back policies barring city staff from working with ICE.

Adams’ detractors believe his leniency on the issue is an attempt to curry favor with the Trump administration, which recently ordered the Department of Justice to drop the mayor’s federal corruption charges.

Hearing could cost sanctuary cities federal funding

The four cities have struggled to manage the influx of migrants from the southern border, collectively spending billions of dollars on shelter and support services. But Wednesday’s hearing could strip sanctuary cities of some federal funding.

U.S. Attorney General Pam Bondi has already sued the state of New York and the city of Chicago, alleging they have obstructed the federal government from enforcing immigration laws. Shortly after Trump took office, the Department of Justice directed federal prosecutors to investigate whether local officials should face legal action for resisting federal immigration laws.

In addition to the two lawsuits, Bondi issued a memo in early February stating that sanctuary jurisdictions will not have access to federal funds from the Department of Justice.

Trump talks immigration in joint address

The president leaned into immigration during his address to Congress on Tuesday night, casting the decadeslong border crisis as merely a failure of Democratic leadership.

“Our friends in the Democrat party kept saying we needed new legislation, ‘We must have legislation to secure the border.’ But it turned out that all we really needed was a new president,” Trump said.

Trump added that his predecessor, former President Joe Biden, “didn’t just open our borders, he flew illegal aliens over them to overwhelm our schools, hospitals and communities throughout the country.”

There is no evidence of Biden funding flights for migrants to enter the U.S.

‘s Jeff Arnold and Alicia Nieves contributed to this report.