A coalition of four Democratic U.S. congresswomen targeted in recent remarks by president Donald Trump, responded to the president on Monday accusing him of promoting a "white nationalist agenda" and vowed not to be "silenced." 

Trump lashed out at the four freshman progressive Democratic congresswomen on social media, saying if they're not happy in the United States, they can "leave" and fix the "crime infested places from which they came", while accusing them of being "pro Al-Qaeda."

"All they do is complain," Trump told reporters at a "Made in America" event at the White House featuring U.S.-manufactured products.

"These are people that hate our country," he said. "If you're not happy here, you can leave." 

Trump also accused the four Democratic congresswomen – who are of Hispanic, Arab and African-American origin – of having "love" for U.S. "enemies like Al-Qaeda." 

Asked by a reporter whether he was concerned that many people saw his comments as racist, Trump said: "It doesn't concern me because many people agree with me." 

The president began his xenophobic attacks on the lawmakers with a series of tweets on Sunday, prompting outrage from Democrats – and, initially, awkward silence from Republicans. 

Several hours after his remarks, the four – Alexandria Ocasio-Cortez of New York, who is of Puerto Rico origin, Ilhan Omar of Minnesota, who is of Somali origin, Rashida Tlaib of Michigan, the first Palestinian-American woman elected to Congress, and Ayanna Pressley of Massachusetts, who is African-American - hit back in a news conference. 

Pressley condemned Trump's "xenophobic and bigoted" comments and said "we will not be silenced." 

Omar said Trump made a "blatantly racist attack" on four lawmakers "of color." 

"This is the agenda of white nationalists," she said. 

Omar and Tlaib repeated calls for Trump to be impeached. 

On Monday, several in Trump's party began to speak up. 

"My view is that what was said and what was tweeted was destructive, was demeaning, was disunifying, and frankly it was very wrong," said Senator Mitt Romney, a Republican from Utah. 

"There is no excuse for the president's spiteful comments. They were absolutely unacceptable and this needs to stop," said Senator Lisa Murkowski, a Republican from Alaska. "We must demand a higher standard of decorum and decency." 

Senator Susan Collins of Maine said she disagreed with the policies espoused by the "far-left" Democratic lawmakers but added "the president's tweet that some members of Congress should go back to the 'places from which they came was way over the line, and he should take that down." 

For Republican Senator Pat Toomey of Pennsylvania, "The citizenship of all four is as valid as mine." 

"They are entitled to their opinions, however misguided they may be," he added. 

Will Hurd, the only black Republican in the House of Representatives, told CNN that Trump's tweets were "racist and xenophobic" and "behavior that's unbecoming of the leader of the free world." 

Senator Tim Scott, a black Republican from South Carolina, criticized Trump for using "unacceptable personal attacks and racially offensive language" while Republican Representative Mike Turner of Ohio said the remarks were "racist and he should apologize." 

'Cold, hard strategy' 

Trump's comments appear to be aimed at galvanizing his mostly white electoral base ahead of the 2020 presidential vote, while also stoking divisions among his political opponents. 

"With his deliberate, racist outburst, @realDonaldTrump wants to raise the profile of his targets, drive Dems to defend them and make them emblematic of the entire party," said David Axelrod, who served as chief strategist for Barack Obama's two terms at the White House.

"It's a cold, hard strategy," Axelrod said on Twitter. "Fasten your seat belts, it will only get worse as the election approaches." 

"The voters will decide," Trump told reporters. 

"If (the Democrats) want to gear their wagons around these four people, I think they're going to have a very tough election, because I don't think the people of the United States will stand for it." 

In his initial Twitter attack on Sunday, Trump – who before becoming president pushed the racist "birther" conspiracy theory that Obama was not born on U.S. soil – said the congresswomen came from corrupt, poorly managed countries to which they should return. 

Ocasio-Cortez, Tlaib and Pressley were born in the United States while Omar came to the United States as a refugee from war-torn Somalia when she was a child. 

"You have somebody that comes from Somalia, which is a failed government, a failed state, who left Somalia, who ultimately came here and now is a congresswoman who's never happy," said Trump.

He accused the lawmakers of using anti-Semitic language and voicing hatred for Israel, even suggesting they are communists. 

Nancy Pelosi, the Democratic speaker of the House of Representatives, has had a tenuous relationship with the four left-leaning first-term congresswomen but she jumped to their defense. 

"When @realDonaldTrump tells four American Congresswomen to go back to their countries, he reaffirms his plan to 'Make America Great Again' has always been about making America white again," tweeted Pelosi. 

Pelosi also said she was seeking Republicans to co-sponsor a resolution in the House "condemning the president's xenophobic tweets" and "characterization of immigrants." 

Ocasio-Cortez, also known as AOC, tweeted: "the President's words yday, telling four American Congresswomen of color 'go back to your own country' is hallmark language of white supremacists." 

"Trump feels comfortable leading the GOP into outright racism, and that should concern all Americans," she said.