President Donald Trump on Sunday described a group of Democratic congresswomen of colour as foreign-born troublemakers who should go back to where they came from, ignoring that the women are American citizens and all but one were born in the US.
Mr Trump’s tweets drew sharp rebukes from Democrats, who derided his remarks as racist.
House Speaker Nancy Pelosi said the president wanted to “make America white again”.
Meanwhile, 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 was almost certainly referring to representative Alexandria Ocasio-Cortez of New York and her allies, who have become known as “the squad”.
The others are representatives Ilhan Omar of Minnesota, Ayanna Pressley of Massachusetts and Rashida Tlaib of Michigan. Only Ms Omar, from Somalia, was not born in the US.
Ms Ocasio-Cortez swiftly denounced Mr Trump’s remarks.
“Mr President, the country I come from, and the country we all swear to, is the United States,” she tweeted.
With his remarks, Mr Trump again interfered in a rift between Ms Pelosi and the liberal congresswomen, after offering an unsolicited defence of the Democratic speaker days earlier.
Ms Pelosi has been seeking to minimise Ms Ocasio-Cortez’s influence in recent days, prompting her to accuse the speaker of trying to marginalise women of colour.
“She is not a racist,” Mr Trump said on Friday. But on Sunday, his tone changed.
“So interesting to see ‘progressive’ Democrat congresswomen, who originally came from countries whose governments are a complete and total catastrophe, the worst, most corrupt and inept anywhere in the world [if they even have a functioning government at all], 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,” he said on Twitter.
“Why don’t they go back and help fix the totally broken and crime-infested places from which they came?
“These places need your help badly – you can’t leave fast enough. I’m sure that Nancy Pelosi would be very happy to quickly work out free travel arrangements.”
The attacks may have been meant to widen the divides within the Democrats caucus, which is strained with internal debates on liberal policies and on whether to proceed with impeachment proceedings against Mr Trump.
Instead, Democrats as one voice denounced the comments.
"Unfortunately, there is an American tradition of telling people to go back to where they came from," New York City Mayor Bill de Blasio, a Democratic presidential contender, said on CNN's State of the Union.
“It’s a very bad tradition that we need to weed out of our nation because we are a nation of immigrants. That is who we are by our nature for hundreds of years. But you don’t expect to hear it from the president.”
It was far from the first time that Mr Trump has been accused of holding racist views.
His political career was launched after he falsely claimed that President Barack Obama was not born in the US.
In his campaign kickoff in June 2015, he called many Mexican immigrants “rapists”.
And last year, during a White House meeting on immigration, he wondered why the US was admitting so many immigrants from countries such as Haiti, El Salvador and African nations, which he referred to with an expletive.
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 Somali native 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 the age of 12, teaching herself English by watching American TV, and eventually settled with her family in Minneapolis.
Ms Tlaib was born in Detroit.