
The boos came when Vance and his wife Usha were shown on a large screen at the San Siro stadium, both applauding and waving flags as the US athletes filed past in the ceremonial parade.
Some of the loudest applause during the parade was for the Ukraine team.
Russian athletes taking part as neutrals because of Olympic sanctions following Russia’s invasion of Ukraine were not included in the parade.
Hundreds protested in Milan earlier on Friday against Vance’s visit and the presence of some agents from the US immigration enforcement agency ICE to help protect the American delegation.
Vance also on Friday met with Italian Prime Minister Giorgia Meloni, a fellow conservative who is close to US President Donald Trump, and hailed “shared values” with Italy.