US President Donald Trump has been condemned by politicians in his own country after a series of tweets aimed at four congresswomen.
Since US President Donald Trump took up office in 2016, his use of social media has attracted worldwide attention.
He has often posted controversial statements and made personal comments about people, including other politicians and celebrities.
In the latest tweet to attract attention, Mr Trump made a comment about four US congresswomen, for which he has been accused of racist behaviour.
On Tuesday, the president dismissed this accusation, saying: "Those tweets were NOT racist. I don't have a racist bone in my body!"
Read on to find out more about what he said and what the response has been.
In a three-tweet thread, Mr Trump indirectly accused four congresswomen - Alexandria Ocasio-Cortez, Rashida Tlaib, Ayanna Pressley and Ilhan Omar - of "viciously" criticising him and the US.
The president did not name the women he was talking about, but the context makes a link with who he is talking about.
He wrote: "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.
"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."
The four congresswomen - sometimes nicknamed 'the squad' - are Ilhan Omar, Alexandria Ocasio-Cortez, Rashida Tlaib and Ayanna Pressley.
Three of the women were born in the US and one, Ms Omar, was born in Somalia and came to the US as a child.
They are all Democrats, while Mr Trump is a Republican.
All four were elected during the 2018 mid-term elections and represent a group of young political leaders that many see as a backlash to Donald Trump's 2016 election.
On Friday, Ms Ocasio-Cortez, Ms Tlaib and Ms Pressley spoke to a government group about conditions in a migrant detention centre they had visited for people being held on the Mexico-US border.
Mr Trump defended border agents and conditions at the centre. He then posted the series of tweets.
Saying four women of colour who are all US citizens should "go back" to where they came from is seen by lots of people as racially charged language.
Many people say that what he tweeted is the same as racist language telling citizens from minority backgrounds to "go home".
Trump has responded saying that the tweets were not racist. When asked by reporters if his message had been racist, he did not apologise.
"If you're not happy here, then you can leave," he said. "As far as I'm concerned, if you hate our country, if you're not happy here, you can leave. And that's what I say all the time."
For many, the comments are a step too far even for Mr Trump, who has a history of controversial comments.
Despite the criticism, Mr Trump took to Twitter on Monday morning after the tweets calling on the women themselves to apologise.
"When will the Radical Left Congresswomen apologise... for the foul language they have used, and the terrible things they have said," he said.
The four women who were attacked have dismissed the tweets as a distraction from what they consider to be much bigger problems of the president's administration.
Those Tweets were NOT Racist. I don't have a Racist bone in my body!
Ms Pressley dismissed the president's efforts "to marginalise us and to silence us".
She added: "Our squad includes any person committed to building a more equitable and just world."
Ms Tlaib called it "simply a continuation of his racist, xenophobic playbook". She also tweeted calling for Mr Trump's impeachment.
Ms Ocasio-Cortez responded: "On top of not accepting an America that elected us, you cannot accept that we don't fear you either."
Ms Omar said "you are angry that people like us are serving in Congress and fighting against your hate-filled agenda" and also called for his impeachment.
Democrats have strongly criticised the president for what he said, with many calling it a racist attack.
Senior Republicans have been less outspoken about it, but lower-ranking members of Mr Trump's political party have been more direct.
Tim Scott - the only African-American Republican in the Senate - called the president's words "racially offensive", while Republican Congressman Will Hurd, who is also African-American, described the comments as "racist and xenophobic".
On Tuesday the US House of Representatives, which is one part of US government which makes laws, voted to symbolically condemn the president.
The resolution denounced Mr Trump's "racist comments that have legitimised fear and hatred of New Americans and people of colour".
Tuesday's vote passed by 240 votes to 187 in the Democratic-controlled chamber. Four Republicans and the chamber's sole independent, former Republican lawmaker Justin Amash, joined all 235 Democrats to approve the resolution.
There have also been calls for impeachment proceedings against President Donald Trump because of these tweets but the move has been blocked in the US House of Representatives.
Texas Democrat Al Green filed the resolution but the measure failed to win enough support, with his fellow Democrats voting overwhelmingly against.
Mr Trump said the "ridiculous" attempts to impeach him were now "over".
Canadian Prime Minister Justin Trudeau commented: "That is not how we do things in Canada." New Zealand's Prime Minister Jacinda Ardern said she "completely and utterly" disagreed with Mr Trump.
Both Jeremy Hunt and Boris Johnson - the two candidates to be the next UK prime minister - have spoken out against what he said.
Mr Hunt said he was "utterly appalled" by Mr Trump's tweets, while Mr Johnson said "you simply cannot use that kind of language about sending people back to where they came from".
Current Prime Minister Theresa May said the remarks were "completely unacceptable".
Labour leader called the remarks "racist" and criticised the Tory leadership candidates for not saying the same.