Donald Trump has hit back after being accused of making "racist and disgusting" remarks about Democratic congresswomen from black and minority ethnic (BAME) backgrounds.
The US president shrugged off sharp criticism over tweets in which he said four outspoken liberal congresswomen of colour should "go back and help fix" their "broken and crime infested" countries.
In a tweet on Sunday night, he wrote: "So sad to see the Democrats sticking up for people who speak so badly of our country and who, in addition, hate Israel with a true and unbridled passion.
"Whenever confronted, they call their adversaries, including Nancy Pelosi, 'RACIST'.
"Their disgusting language and the many terrible things they say about the United States must not be allowed to go unchallenged.
"If the Democrat Party wants to continue to condone such disgraceful behavior, then we look even more forward to seeing you at the ballot box in 2020!"
The dispute began after Mr Trump appeared to refer to Alexandria Ocasio-Cortez and her allies in what has become known as "the squad".
The other representatives are Ilhan Omar of Minnesota, Ayanna Pressley of Massachusetts and Rashida Tlaib of Michigan.
Ms Omar, from Somalia, is the only one who is foreign-born.
Mr Trump had written on Twitter on Sunday: "So interesting to see 'Progressive' Democratic Congresswomen, who originally came from countries whose governments are a complete and total catastrophe, the worst, most corrupt and inept anywhere in the world... now loudly and viciously telling the people of the United States, the greatest and most powerful nation on earth, how our government is to be run.
"Why don't they go back and help fix the totally broken and crime infested places from which they came.
"Then come back and show us how it is done."
Ms Tlaib wrote on Twitter in the hours after the tweet was posted: "Want a response to a lawless and complete failure of a president?
"He is the crisis. His dangerous ideology is the crisis. He needs to be impeached."
Republican representative Justin Amash of Michigan, a critic of Mr Trump who recently took steps to leave his party, called the remarks "racist and disgusting".
The president's tweets drew a rebuke from House Speaker Nancy Pelosi who said the president wants to "make America white again".
Mr Trump has entered into a rift with Ms Pelosi and the liberal congresswomen after offering an unsolicited defence of the Democratic speaker days earlier.
The House Speaker has been seeking to minimise Ms Ocasio-Cortez's influence in recent days, prompting the congresswomen to accuse her of trying to marginalise women of colour.
Mr Trump defended Ms Pelosi on Friday, saying: "She is not a racist."
Ms Ocasio-Cortez, who is of Puerto Rican descent, was born in the Bronx, New York, and raised in suburban Westchester County.
Ms Pressley, the first black woman elected to the House from Massachusetts, was born in Cincinnati.
Ms Omar, the first woman of Somali descent elected to Congress and one of its first Muslim women, was born in Somalia but spent much of her childhood in a Kenyan refugee camp as civil war tore apart her home country.
She immigrated to the US at age 12, teaching herself English by watching American TV and eventually settling with her family in Minneapolis.
Ms Tlaib, the daughter of Palestinian immigrants, was born in Detroit.