Donald Trump has insisted his performance in a poll assessing his six-month approval rating is "not bad" – despite recording the lowest rating of any president since it started being conducted in the 1940s.

Just 36 per cent of Americans endorsed his job performance, down from another record low of 42 per cent at the 100-day mark, in a joint survey by The Washington Post and ABC News. Fifty-eight per cent disapproved of his first six months, most of them "strongly".

The previous worst approval rating after half a year in the White House was 39 per cent, given to Gerald Ford in 1975.

Mr Trump's deterioration in support comes amid questions over his election campaign's links to Russia, doubts over his ability to negotiate on a world stage, and unpopular policies at home.

Forty-eight per cent of people think the US's place as a global leader has weakened under Mr Trump, compared to 27 per cent who say it has strengthened, the poll found.

Sixty-three per cent of Americans felt a meeting between the President's son Donald Trump Jr and a Russian lawyer who claimed to have damaging information about Hillary Clinton was "inappropriate". Only 26 per cent of those survey said it was appropriate.

However, Mr Trump took to Twitter to denigrate the poll, saying it had been "just about the most inaccurate" during the election last year. He added that his "almost 40 per cent" rating "is not bad at this time".

Earlier, Mr Trump claimed his son had been "scorned by the Fake News Media". "With all of its phony unnamed sources & highly slanted & even fraudulent reporting, #Fake News is distorting democracy in our country," he wrote.

His latest attack on the media came hours after the poll results emerged, although he did not refer to them.

The survey, carried out for each US president since Harry S Truman, found only a third of Americans trusted Mr Trump to negotiate on the world stage. Forty-seven per cent said they had no trust in him, despite the billionaire businessman's boasts about his deal-making. Even fewer trusted the President in talks with Vladimir Putin specifically.

Mr Trump's healthcare plans were also unpopular, with less than a quarter of those surveyed preferring the Republican bill to existing laws. Half of Americans preferred Obamacare to the proposals the Republicans have drawn up to replace it.

Mr Trump's 36 per cent overall approval rating is a close to a mirror image of his predecessor's score after six months. Fifty-nine per cent of Americans felt Barack Obama was doing a job good after half a year in the White House. The Democrat's all-time lowest rating was 40 per cent, which came after years in the White House.