President Donald Trump rehashed longstanding grievances over the Russia investigation that shadowed much of his first term, lashing out Tuesday following a new report from his intelligence director aimed at casting doubt on long-established findings about Moscow's interference in the 2016 election.

Donald Trump has accused Barack Obama of "treason", claiming he plotted to sabotage his first presidency by linking him to alleged Russian election meddling. "They tried to steal the election," Trump said at the White House as he claimed Obama had sought to undermine his 2016 victory over Hillary Clinton.