21 Savage attends an event in New York City on Nov. 5, 2018. Roy Rochlin / Getty

The attorney for rapper 21 Savage says Immigration and Customs Enforcement (ICE) is trying to "intimidate" him into leaving the U.S. after arresting him for allegedly being in the country illegally.

On Sunday, ICE agents arrested the rapper, whose real name is Shayaa Bin Abraham-Joseph, and said he is a United Kingdom national who has been living in the U.S. illegally since the mid-2000s. His lawyer says ICE is refusing to release 21 Savage on any bond amount even though he has not been charged with a crime.

"This is a civil law violation, and the continued detention of Mr. Abraham-Joseph serves no other purpose than to unnecessarily punish him and try to intimidate him into giving up his right to fight to remain in the United States," the attorney, Charles H. Kuck, said in a statement. "He rose above the difficult circumstances of his youth to achieve success and make contributions to our society that rival any of those by a natural born citizen."

Get Breaking News Delivered to Your Inbox

The statement said 21 Savage's family overstayed their visas after bringing him to the U.S. in 2005, leaving him "without legal status through no fault of his own." It also noted that 21 Savage has children who are American citizens, which makes him eligible for relief for deportation.

"We and he will fight for his release, for his family, and his right to remain in our country. No one would expect less from him," Kuck said.

Kuck's statement said 21 filed for a U-Visa in 2017, and federal officials took no action until arresting him in Atlanta on Sunday. The nonimmigrant U-Visa is reserved for people and immediate family members who have "suffered mental or physical abuse and are helpful to law enforcement or government officials in the investigation or prosecution of criminal activity," according to ICE's website. The statement did not say why the rapper filed for this visa.

Kuck's office and ICE did not immediately return messages from CBS News on Monday. ICE said Sunday that the 26-year-old rap star is being held in Georgia and would be placed into removal proceedings in federal immigration court.