US President Donald Trump has pressured fellow Republicans in the US House of Representatives to stand with him and vote against a symbolic measure condemning his racially charged attacks on four Democratic congresswomen.

Democrats, who have a majority in the House, were expected to pass the symbolic resolution of condemnation this evening. But it is Republican representatives who will be in the spotlight as they will be forced to either vote against their party's leader, who has strong support among conservatives, or effectively defend him.

Outrage over Mr Trump's Sunday tweetstorm - in which he told four prominent minority Democratic congresswomen to "go back and help fix the totally broken and crime infested places from which they came" - has since diverted attention from all other business in Washington.

All four representatives are US citizens; three were born in the United States.

Only a handful of Republican representatives have spoken out against Mr Trump's tweets about the congresswomen, doing so in muted tones.

"These are our sisters," House Speaker Nancy Pelosi said of the four women targeted by Mr Trump, who are in their first terms in Congress, during a closed caucus meeting, according to an aide who was present.

Ms Pelosi said she hoped some Republicans would support the resolution. "If they can't support condemning the words of the president, well, that's a message in and of itself," she said.

The women - Alexandria Ocasio-Cortez of New York, Ilhan Omar of Minnesota, Ayanna Pressley of Massachusetts and Rashida Tlaib of Michigan - have been critical of Mr Trump, as well as of the current Democratic leaders of the House, straining party unity in that chamber.

Mr Trump has a history of what critics consider race-baiting. He led a movement that falsely claimed former President Barack Obama was not born in the United States and he said after a deadly, white supremacist-led rally in Charlottesville, Virginia, that "both sides" were to blame for violence there.

Senate Republican Leader Mitch McConnell has said he thought "everybody ought to tone down their rhetoric" and focus on issues, but he stopped short of condemning Mr Trump's remarks.

"The president is not a racist and I think the tone of all of this is not good for the country but it's coming from all different ideological points of view," Mr McConnell said.

The House resolution, seen by Reuters late yesterday, said the House "strongly condemns President Donald Trump's racist comments that have legitimised and increased fear and hatred of new Americans and people of colour."

House Republican Leader Kevin McCarthy said he would encourage his members to vote against the resolution condemning Mr Trump.

"It's all politics," Mr McCarthy told reporters.

Mr Trump later retweeted Mr McCarthy's comments and thanked him.

Mr Trump's attacks on the four progressive congresswomen have been viewed as an effort to divide the Democrats, who won control of the House of Representatives in 2018 and have the power to thwart his legislative agenda.

Mr Trump has sought to highlight proposals from the progressive wing of the Democratic Party, which he calls extreme, as he seeks to attract moderates - and energise his political base -ahead of the November 2020 presidential elections.

Mr Trump was asked by reporters at the White House where he thought the four American lawmakers should go.

"It's up to them. Do what they want. They can leave. They can stay. But they should love our country, and they should work for the good of our country," Mr Trump said, adding complaints about some of their past remarks.

Earlier, Mr Trump had warned Republicans on Twitter against voting against him. "Those Tweets were NOT Racist. I don't have a Racist bone in my body! The so-called vote to be taken is a Democrat con game. Republicans should not show 'weakness' and fall into their trap."

In response, Ms Ocasio-Cortez tweeted: "You're right, Mr President - you don't have a racist bone in your body. You have a racist mind in your head, and a racist heart in your chest.