Scott Pruitt, Donald Trump's embattled chief of the Environmental Protection Agency (EPA), has resigned after a string of scandals led to damaging headlines.

Mr Trump announced the news on Twitter, writing: "I have accepted the resignation of Scott Pruitt as the Administrator of the Environmental Protection Agency."

He added: "Within the Agency Scott has done an outstanding job, and I will always be thankful to him for this." Mr Trump gave no reason for his departure.

Mr Trump said Mr Pruitt's deputy, the former coal lobbyist Andrew Wheeler, would take over Monday as acting head of the agency.

"I have no doubt that Andy will continue on with our great and lasting EPA agenda," the US leader tweeted. "We have made tremendous progress and the future of the EPA is very bright!"