Austin Mayor Steve Adler and other mayors are headed to Washington, D.C., to seek clarity on what a "sanctuary city" is during a meeting Tuesday with Attorney General Jeff Sessions.

Adler said in a blog post on Medium that, with so much on the line, including federal funding, "mayors need to know what is meant by a term being used by a lot of people to mean many different things."

"Surprisingly, it seems most people think a 'sanctuary city' is one where police protect criminals by refusing to enforce federal immigration laws," Adler wrote. "I’m not sure there are such cities, and certainly Austin is not one. We follow the law and want criminals in jail, not on our streets."

On Friday, the Justice Department sent letters to at least eight jurisdictions, asking for proof that they comply with federal immigration laws. Neither Austin nor Travis County received a letter.

Adler said that, in effect, it appeared those jurisdictions were officially being designated as "sanctuary cities."

He is attending the meeting with a group that includes Mayor Mitch Landrieu of New Orleans, one of the cities that received a letter. Chicago; Philadelphia; Las Vegas; Miami; Milwaukee; New York City; Cook County, Illinois; and the California Department of Corrections and Rehabilitation were also singled out.

Bob Libal, executive director of the immigrant advocacy group Grassroots Leadership, told KUT's Nathan Bernier he hopes the mayor sends a message that Travis County and Austin are going to stand strong.

"And that we are going to actually implement policies that go even further than what we have right now to undo the cooperation between Immigration and Customs Enforcement and our local law enforcement,” he said.

The Justice Department said last month that it plans to withhold up to $4.1 billion from "sanctuary" jurisdictions, following through on an executive order President Donald Trump issued in January.

A delegation of mayors had a similar meeting with Homeland Security Secretary John Kelly last month following raids by Immigration and Customs Enforcement agents. Adler said he walked away from that meeting unclear about where Austin stands in the administration’s crackdown on sanctuary cities, but that he was encouraged Kelly had said ICE was focusing on dangerous criminals.

The meeting with Sessions comes as the Texas House takes up a sanctuary cities bill the Senate passed in February. The bill would deny funding to entities that don’t enforce immigration laws and punish local governments if their law enforcement agencies fail to honor ICE requests to hand over immigrants in custody for possible deportation.