The US president signed resolutions to roll back California laws designed to promote the use of electric vehicles.

United States President Donald Trump has signed a series of congressional resolutions to roll back standards in California that would have phased out petrol-powered cars and promoted the use of electric vehicles (EVs).

But Thursday’s signing ceremony gave Trump a platform to strike blows against several of his political foes, including the Democratic leadership of California and ally-turned-critic Elon Musk.

Musk famously leads the electric vehicle company Tesla. California, meanwhile, has long been a Democratic stronghold, and since taking office for a second term in January, Trump has continuously sparred with its governor, Gavin Newsom.

Thursday’s resolutions gave Trump a chance to skewer one of Newsom’s signature environmental achievements: a state mandate that would have gradually required new cars in California to produce zero greenhouse gas emissions.