Anti-Kings protests begin across the U.S. and the National Guard is on standby.

Planned protests against President Donald Trump began Saturday in New York City, the first of more than 2,500 rallies organized across the United States.

Thousands of people have already filled Times Square for the event organized by No Kings, a coalition of left-wing groups.

Demonstrations under their banner in June drew more than 5 million people across the country and were largely peaceful.

Trump allies accused the protesters of being allied with the far-left Antifa movement and denounced what they called “hate-against-America rallies.”

Republican governors in several U.S. states have placed National Guard troops on standby, but it is unclear how noticeable the military presence will be.

Protests are expected to continue throughout the country on this day. In Washington, DC, the event is expected to begin around noon local time, with Vermont Senator Bernie Sanders as the keynote speaker.

Protest organizers said the rally would challenge President Trump’s “authoritarianism.”

“The president thinks his rule is absolute,” they say on their website.

“But America has no king, and we will not back down to chaos, corruption, and cruelty.”

Across Europe, protesters took to the streets of Berlin, Madrid and Rome to show solidarity with their American counterparts.

In an interview with Fox News that was scheduled to air on Sunday but was teased on Saturday, Trump appeared to address the upcoming rally.

“King! This is not an act,” Trump said in a video preview of the interview. “They call me king. I am not king.”

According to CNN, Kansas Senator Roger Marshall said ahead of the rally, “We need to get the National Guard out.”

“I hope it’s peaceful. I don’t think it will be.”

Texas Gov. Greg Abbott activated the National Guard ahead of protests planned in Austin on Thursday.

He said troops would be needed because of “planned Antifa-related protests.”

Democrats condemned the move, with top Democratic leader Jin Woo claiming, “Sending armed soldiers to suppress peaceful protests is what kings and dictators do, and Greg Abbott has proven himself to be one of them.”

Virginia Republican Governor Glenn Youngkin also ordered the National Guard to be activated.

Earlier this week, actor Robert De Niro, a regular critic of Trump, shared a short video urging Americans to join him in “nonviolently speaking out.”

“We have had democracy for 250 years – often challenging, sometimes messy and always essential,” he said.

“Now we have a would-be king who wants to take it away from us: King Donald I.”

Among the celebrities expected to attend the No Kings rally are Jane Fonda, Kerry Washington, John Legend, Alan Cumming and John Leguizamo.