Hillary Clinton has officially announced her 2016 presidential run Sunday with a video on her newly launched campaign website.

The video focuses on different Americans telling their stories. Clinton says in the video that "everyday Americans need a champion. I want to be that champion."

John Podesta, a top adviser to Clinton, told alumni of her first presidential campaign in an email ahead of the site's launch: "It's official: Hillary's running for president."

The former first lady, U.S. senator and secretary of state will focus her campaign on middle-class economic security and working families, advisers have said.

Advisers have said that after the campaign gets officially underway, Clinton would attend small events with residents of early-voting states.

Supporters held a "Ready for Hillary" rally in Manhattan on Saturday ahead of the announcement. If elected, she would be the first female U.S. president.

On the Republican side, Sens. Rand Paul and Ted Cruz have announced their own 2016 runs. Ahead of Clinton's announcement, Jeb Bush and other possible presidential hopefuls released their own statements and videos pouncing on the former secretary of state.