US President Trump on Monday slammed California Gov. Gavin Newsom (D) for signing a memorandum of understanding with the United Kingdom to address climate change.

"The U.K.`s got enough trouble without getting involved with Gavin Newscum," Trump told Politico, referring to the California governor.

"Gavin is a loser. Everything he`s touched turns to garbage. His state has gone to hell, and his environmental work is a disaster," he added.

Trump worked to repeal clean energy measures during his first year back in office and has often clashed with Newsom amid his attempts to declare himself as a leader on a global stage.

The California governor is a likely contender for the 2028 presidential election and has made appearances at major international events including the World Economic Forum in Davos, Switzerland, and the 30th United Nations Climate Change Conference (COP30) in Brazil.

His Monday deal with the United Kingdom garnered a $1 billion investment from the British-based Octopus Energy company.

The funds will be used to back two Californian carbon removal companies in grassland restoration and reforestation projects to transform degraded land into CO2-absorbing assets, per a press release.

Newsom`s office said the president`s comments regarding the foreign agreement are based upon his loyalty to nonrenewable energy sourcing.

"Donald Trump is on his knees for coal and Big Oil, selling out America`s future to China. Governor Newsom will continue to lead in his absence," a spokesperson told The Hill.

"Foreign leaders are rejecting Trump and choosing California`s vision for the future," they added.

The White House did not immediately respond to a request for comment.

U.K. Energy Secretary Ed Miliband lauded the California agreement as a measure that would help the country take back "control of our energy to cut bills, create jobs, and tackle the climate crisis."