Washington, Aug 27 (TIWN) US President Donald Trump has called for drug tests to be administered before his first presidential debate with Democratic candidate Joe Biden next month, it was reported.

Mr Trump told the Washington Examiner he had noticed a sudden improvement in Mr Biden's performance in the Democratic TV debates.

The president offered no evidence his rival might be on drugs other than to say: "I'm pretty good at this stuff."

Mr Biden and Mr Trump will have three debates before the 3 November election.

Back in 2016, Mr Trump suggested his then-Democratic rival, Hillary Clinton, had been "getting pumped up" before their debates and challenged her to take a drug test ahead of their final live TV encounter. The Clinton camp brushed aside his challenge.

On Wednesday, the president - who is set to deliver his keynote address to the ongoing Republican party convention on Thursday - made a similar claim, arguing that Mr Biden's debating ability had improved markedly in the final debate.