Donald Trump's approval rating continues to plumb historic lows ahead of the Republican Party's national convention — but the US president still believes his brand can boost close-race candidates who will be "showcased" on stage.

Despite Donald Trump’s low approval ratings, he said to “pretend I’m on the ballot,” encouraging voters to head to the polls.

WASHINGTON, Sept 8 — US Republicans will gather in Dallas, Texas, next week for a two-day convention aimed at convincing voters that Donald Trump is effectively on the ballot in...