Four people have been charged with leaking information from the Trump administration, the US attorney general announced on Friday, as he took an aggressive stand against the deluge of leaks that have plagued the first six months of the presidency.

Jeff Sessions, who was taunted by his boss, President Donald Trump, for being weak on leakers, said that he would leave no stone unturned in the hunt for the culprits.

His remarks came after the highly-damaging, and highly unusual, leak of transcripts of Mr Trump’s telephone calls with the leaders of Mexico and Australia.