(NewsNation) — Some migrants who are being bused from the southern border to sanctuary cities across are calling Texas Gov. Greg Abbott “El Transportador,” or “the transporter.”

Sources who have been bused from the U.S.-Mexico border to cities like New York, Washington, D.C. and Chicago told NewsNation they’re grateful for the help and a free ride closer to family.

According to the Texas Tribune, Abbott’s move to relocate 8,900 migrants under “Operation Lone Star” has cost $12.7 million.

While the move has been criticized by officials in the Democrat-controlled cities, advocacy groups in Texas say the operation has strengthened their work.

“What used to be a very specific borderland issue now, because of Gov. Abbott’s initial response — his tactics of busing migrants to other parts of the country — has actually brought us into closer contact with colleagues in other communities,” said Marisa Limon Garza, executive director of El Paso’s Las Americas Immigrant Advocacy Center.

Limon said representatives from New York City Mayor Eric Adams were on the border this week, requesting advice from Las Americas to better understand the needs of the migrants getting off buses the Texas governor put them in so they can address those needs.

Recently, Chicago Mayor Lori Lightfoot criticized Abbott for not cooperating with the cities migrants are being bused to. The first bus dropped migrants off at Chicago’s Union Station at 7:30 p.m. last Wednesday.

“(Abbott) tries to send human beings — not cargo, not freight — but human beings across the country to an uncertain destination,” Lightfoot said. “He is manufacturing a human crisis and it makes no sense to me.”

Abbott has repeatedly said the busing is necessary to address “the border crisis,” a situation he places squarely on President Joe Biden.

“[Biden’s] inaction at our border is putting the lives of Texans at risk & is overwhelming our communities. Texas is doing Biden’s job to secure the border,” he wrote on Twitter.

But the cooperation Lightfoot is seeking may be where immigration advocacy groups are best suited to help.

“You can believe we are going to start seeing more of a network of support that, yes, is connected to the border, but it’s not going to be us being the only group carrying the water,” Limon told NewsNation affiliate Border Report. “Instead, it will be more organizations, more municipalities and governments taking a concerted effort to work together in a humanitarian response to meet the needs of people on the move.”