US immigration agents have conducted raids at nearly 100 7-Eleven stores across the country in a crackdown on unauthorised workers, officials say.

Immigration and Customs Enforcement (ICE) agents arrested 21 people in the raids, which were carried out in 17 states from California to Florida.

An ICE spokesman said the move sent a “strong message” to businesses that chose to employ undocumented staff.

President Trump has made tackling illegal immigration a priority.

Following Wednesday’s raids, acting ICE director Thomas Homan said the agency was simply enforcing the law, adding that those who did not comply would be “held accountable”.

“Businesses that hire illegal workers are a pull factor for illegal immigration and we are working hard to remove this magnet,” Mr Homan said in a statement.

He added that the crackdown would help to protect jobs for American citizens by “eliminating unfair competitive advantages for companies that exploit illegal immigration”.

ICE agents targeted a total of 98 7-Eleven convenience stores in the raids.

The company later released a statement in relation to the hiring practices at its franchises.

“7-Eleven franchisees are independent business owners and are solely responsible for their employees, including deciding who to hire and verifying their eligibility to work in the United States,” the company said.

It added that it had “terminated” the agreements of franchises convicted of violating the laws.

Under President Donald Trump, ICE has stepped up its efforts to arrest and deport illegal immigrants in the US.

Earlier this week, a decision by the White House to withdraw El Salvador migrants’ right to remain in the US after nearly three decades was condemned by Democratic lawmakers.

The Trump administration said on Monday that the Central American migrants must leave or seek lawful residency, giving them an 18-month grace period.

As a result, hundreds of thousands of migrants face possible deportation from the US.