Trump to Democratic congresswoman Maxine Waters: 'Be careful'

Democratic lawmaker Maxine Waters and US President Donald Trump

US President Donald Trump has stepped up his war of words with Democrats after his spokeswoman was kicked out of a restaurant by its anti-Trump owner.

Democratic lawmaker Maxine Waters encouraged supporters to publicly harass Trump administration officials during a rally on Saturday.

On Monday, Mr Trump warned Ms Waters in a tweet: "Be careful what you wish for Max."

Top Democrat Nancy Pelosi has chided Ms Waters, as well as Mr Trump.

In his tweet on Monday, Mr Trump called Ms Waters a person with "an extraordinarily low IQ" who had "called for harm" to his supporters.

The controversy began on Friday night, when White House press secretary Sarah Sanders was kicked out of the Red Hen restaurant because of her work for President Trump.

"I have a business, and I want the business to thrive," owner Stephanie Wilkinson later told the Washington Post.

"This feels like the moment in our democracy when people have to make uncomfortable actions and decisions to uphold their morals," she continued.

At a rally in Los Angeles on Saturday, Ms Waters encouraged people to act against the Trump administration in similar ways.

"If you see anybody from that Cabinet in a restaurant, in a department store, at a gasoline station, you get out and you create a crowd, and you push back on them," she said at the event, which was filmed and shared on YouTube.

"You tell them they're not welcome anymore, anywhere," the California congresswoman said, calling for Mr Trump's impeachment during the same speech.