British Prime Minister Theresa May has criticised US President Donald Trump for calling on several Democratic congresswomen of colour to "go home".

Axar.az reports citing BBC that the outgoing PM called Trump's words "completely unacceptable", according to her spokesperson.

Trump said the women "originally came from countries whose governments are a complete and total catastrophe". He was referring to four congresswomen - three who were born in the US and one who came as a child refugee.

His remarks were widely condemned as racist, and as having gone beyond previous statements and actions by the president that drew allegations of racism.

Prospective Democratic presidential candidates denounced Trump's tweets as racist and divisive. Republican Party representatives kept quiet. Despite the criticism, President Trump launched another Twitter tirade on Monday morning, calling on the women themselves to apologise.

The women - Alexandria Ocasio-Cortez, Rashida Tlaib and Ayanna Pressley, and Ilhan Omar, who came to the US as a refugee aged 12 - all called the president racist and were been backed by members of the Democratic Party. Ocasio-Cortez was born in the Bronx in New York, approximately 12 miles away from the Queens hospital where Trump was born.