Soldiers are on standby for possible deployment to Minneapolis, a US defence official has told CBS News, the BBC's US partner.
The official said the 1,500 soldiers, currently in Alaska, are an option for the US president if he decided to use active duty military personnel, as anti-Immigration and Customs Enforcement (ICE) demonstrations continued in the city on Saturday.
No decision has yet been made on whether to deploy the soldiers from Alaska, the official said.
Minnesota officials have urged protesters to stay orderly and peaceful during demonstrations after an ICE agent shot dead US citizen Renee Good earlier this month.
The soldiers are part of the 11th Airborne Division in Fort Wainwright, the official added.
It comes as a US federal judge issued an order limiting the crowd control tactics that can be used by ICE agents towards peaceful and unobstructive protesters in Minneapolis.
Judge Katherine Menendez earlier ruled that federal agents cannot arrest or pepper spray peaceful demonstrators, including those monitoring or observing ICE agents.
The state's National Guard has been mobilized and placed on alert by Governor Tim Walz, and other law enforcement officers were deployed to Minneapolis ahead of the anti-ICE demonstrations.
Recent protests in the city were sparked by widespread action by ICE in the city, and follow Good's death on 7 January.
City leaders said Good was there as a legal observer of ICE activity.
But the Trump administration has called her a domestic terrorist.
Good's death sparked protests across the country, with many people holding signs that read Justice for Renee.
