Donald Trump has lashed out at members of his own party as his controversial response to white supremacist violence threatens to engulf his presidency.

US President Donald Trump has denounced the appointment of a special counsel to investigate his campaign's ties with Russia, calling it an unprecedented "witch hunt" that "hurts our country terribly".

In the United States, demonstrators have gathered in the city of North Charleston to protest at the fatal shooting of a black man by a white police officer.