President Donald Trump has said he will sign an executive order to temporarily suspend all immigration to the US because of the coronavirus.

On Twitter, he cited "the attack from the invisible enemy", as he calls the virus, and the need to protect the jobs of Americans, but did not give details.

It was not clear what programmes might be affected and whether the president would be able to carry out the order.

Critics say the government is using the pandemic to crack down on immigration.

Immigration has traditionally been...