HAMBURG, Germany - New York City Mayor Bill de Blasio will deliver the keynote speech Saturday at one of the protests going on outside the G-20 summit in Germany.
The mayor is scheduled to appear in Hamburg at a rally for peace and human rights.
He is expected to speak against President Trump's policies and the rise of populism in Europe.
De Blasio was invited to speak by the mayor of Hamburg.
He is set to return to New York Sunday night.
The mayor was criticized on social media about leaving in the aftermath of the murder of an NYPD officer.
Anti-globalization activists rioted violently for a second night as Hamburg hosted Group of 20 leaders, setting up street barricades, looting supermarkets and attacking police with slingshots and firebombs on Saturday.
Police said riots were extremely aggressive in the early hours of Saturday in the city's Schanzenviertel neighborhood, which is only a few hundred meters (yards) away from the summit grounds.
Hundreds of officers went into buildings to arrest rioters wearing black masks from rooftops while being attacked with iron rods and Molotov cocktails. Thirteen activists were arrested when special units stormed one building.
About 500 people looted a supermarket in the neighborhood as well as smaller stores. Cars were torched and street fires lit as activists built barricades with garbage cans and bikes.
(The Associated Press contributed to this report.)