Former US presidential candidate Kamala Harris says she will not run for governor of California.

Following her unsuccessful 2024 presidential bid, reports suggested Harris was weighing entering next year's election to lead her home state of California, where she had served as a US senator and worked as a prosecutor.

"After deep reflection," the former vice-president, a Democrat, said in a statement on social media, "I've decided that I will not run for Governor in this election."

"For now, my leadership - and public service - will not be in elected office," she added, saying she would share "more details in the months ahead about my own plans."

Her decision leaves the door open for her to mount another try for the White House in 2028, while also removing a possible frontrunner from the race to succeed Governor Gavin Newsom, a fellow Democrat understood to have his own presidential ambitions.

In her statement, Harris appeared to address worries within her own party about its direction and future after she lost November's election to President Donald Trump.

"As we look ahead, we must be willing to pursue change through new methods and fresh thinking—committed to our same values and principles, but not bound by the same playbook," she posted.

Primaries for California's next governor are set to take place in June 2026, before the general election in November. Newsom is completing his second and final term and the new governor will take office in 2027.

Democrats dominate the state's political leadership, and whoever wins the party's nomination will be expected to then take the governorship. Arnold Schwarzenegger, the last Republican to serve as governor, left office in 2011.

An economic powerhouse of America, California would be the world's 5th largest economy if it were a country. It's also home to the Silicon Valley, where companies like Apple and Meta are based, giving its governor, as well as its regulations and laws, influence at the national level.