Milan, Italy - A branch of the ICE will help with security for the Winter Olympics in Italy, the now under-fire agency confirmed Tuesday, sparking anger and warnings they were not welcome.

In a statement overnight to AFP, ICE said: "At the Olympics, ICE's Homeland Security Investigations (HSI) is supporting the US Department of State's Diplomatic Security Service and host nation to vet and mitigate risks from transnational criminal organizations."

It added: "All security operations remain under Italian authority."

It's not known whether the HSI has in the past been involved in the Olympics, or whether this is a first.

Reports had been circulating for days that the agency embroiled in a brutal and deadly assault on immigrant communities could be involved in US security measures for the February 6-22 Games in northern Italy.

According to the ICE website, the HSI investigates global threats, investigating the illegal movement of people, goods, money, contraband, weapons, and sensitive technology into, out of, and through the US.

ICE made clear its operations in Italy were separate from the immigration crackdown, which is being carried out by the Enforcement and Removal Operations (ERO) department.

"Obviously, ICE does not conduct immigration enforcement operations in foreign countries," it said.

The protection of US citizens during Olympic Games overseas is led by the State Department's Diplomatic Security Service (DSS).

Yet the outrage over ICE's operations in the US is shared among many in Italy, especially following the killing of Renee Good and Alex Pretti in Minneapolis this month.

The leftist mayor of Milan, which is hosting several Olympic events, said ICE was "not welcome."

"This is a militia that kills... It's clear that they are not welcome in Milan, there's no doubt about it, Giuseppe Sala told RTL 102.5 radio.

"Can't we just say no to (US President Donald) Trump for once?"

Alessandro Zan, a member of the European Parliament for the centre-left Democratic Party, condemned it as "unacceptable".

"In Italy, we don't want those who trample on human rights and act outside of any democratic control," he wrote on X.

Italian authorities initially denied the presence of ICE and then sought to downplay any role, suggesting they would help only in security for the US delegation.

US Vice President JD Vance and Secretary of State Marco Rubio are attending the opening ceremony in Milan on February 6.

On Monday, the president of the northern Lombardy region, said their involvement would be limited to monitoring Vance and Rubio.

"It will be only in a defensive role, but I am convinced that nothing will happen," Attilio Fontana told reporters.

However, his office then issued a statement saying he did not have any specific information on their presence, but was responding to a hypothetical question.

Interior Minister Matteo Piantedosi was quoted as saying late Monday that "ICE, as such, will never operate in Italy".