Donald Trump, in one of his characteristic impulsive tweets, said that the USA and Russia wanted to create a cyber security unit to monitor worldwide hacking.

But later, Trump tweeted that it wasn't likely to happen after all.

The u-turn came about because Republican politicians don't trust Russia much at all – particularly since American security organisations have evidence that Russia actively meddled in last year's presidential election.

One of the other problems Trump faces is that there are several investigations underway about whether Russia had a part in the presidential campaign.

US intelligence agencies also think that Russia was behind a hack into nuclear power and energy companies, according to a report in the Washington Post over the weekend.