California Governor Newsom blasts Trump for 'dumb' US climate policy at COP30

California Governor Gavin Newsom

California Governor Gavin Newsom on Tuesday blasted US President Donald Trump's "dumb" decision to reverse the federal government's course on climate action.

However, he assured an audience at the COP30 climate summit in Brazil that his state would continue to prioritise green technology, Reuters reported.

Speaking at an event with Germany's vice minister for climate and state-level officials, he lamented the Trump administration's attacks on the fast-growing clean energy economy as ceding the market to China.

"China is flooding the zone and will dominate in the next great global industry," Newsom said in the first of several scheduled appearances at the U.N. climate summit in Brazil's Amazon city of Belem.

A strident political foe of Trump, Newsom has for months been teasing a run for the White House in 2028. Spectators pressed up against a plexiglass barrier to watch him speak on one panel midday Tuesday. Dressed casually in a white business shirt in the sweltering tropical heat, Newsom made a point of casting climate change as a nonpartisan issue -- and listed climate actions made by two Republican presidents from California, Ronald Reagan and Richard Nixon.

Though California is just one of 50 US states, its economy is the world's fourth-largest - making it a key player in influencing markets and energy policy.

Flanked by U.N. security guards, Newsom was holding meetings with other officials from some of the 195 governments participating in the summit.