U.S. Vice President Kamala Harris, building Democratic backing for her sudden presidential run, rallied supporters on Monday with a debut campaign speech vowing to go after Republican nominee and former U.S. President Donald Trump like the courtroom prosecutor she once was.

"I took on perpetrators of all kinds. Predators who abused women, fraudsters who ripped off consumers, cheaters who broke the rules for their own gain," Harris told campaign workers 28 hours after U.S. President Joe Biden, 81, abandoned the 2024 White House race and endorsed her.

"So hear me when I say I know Donald Trump's type. In this campaign, I will proudly — I will proudly put my record against his," said Harris, who was attorney general of California and a U.S. senator before serving as Biden's vice president.