A key Women's March organizer claimed Sunday that she had been kicked off an American Airlines flight earlier in the day and blamed "white male aggression" for the incident.

Tamika Mallory said in a Facebook Live video that, before a flight from Miami to New York, she used a kiosk to change her seat assignment from a middle seat to an aisle seat, the Washington Post reported. But when Mallory went to board, she was told the aisle seat was now taken and she would have to take the middle seat.

The gate agent laughed off Mallory's concerns, according to Mallory, saying that she did not pay for an upgrade and someone else probably just booked the seat before her.

But the national co-chair of the Women's March movement said in her Facebook video that she demanded an apology from the agent, who was also a black woman.

"The issue is not even about the seat. The issue is about the way in which you are speaking to me," Mallory said she told the gate agent.

The pilot, a white man, overheard the conversation and came out to defend his coworker.

"The first words that came out of the pilot's mouth … and this is the part that it just really hurts me … was, ‘Respect goes both ways,'" Mallory said. "And he said, ‘She told you she had nothing to do with your ticket and you had issue with that. What's your problem?'"

Mallory said she threatened to file a complaint.

"You're going to get yourself a one-way ticket off of this plane," he warned, according to Mallory.

Sure enough, when Mallory finally boarded the plane, there was an announcement asking her to come to the front of the plane. The pilot pointed to her and said he wanted her off his plane.

"It definitely was white male aggression. I was singled out, I was disrespected, and he was trying to intimidate me. I was discriminated against," Mallory later told the New York Daily News.

She also tweeted about the incident, writing, "Doesn't matter how much we do and how hard we fight, white men are allowed to treat black women like shit."

American Airlines says it is looking into the allegation.

"We take these allegations seriously, and we have spoken to all involved, including Ms. Mallory," airline spokesman Ross Feinstein said. "Due to an error with a seat change request, Ms. Mallory was informed her requested seat was not available and she was given her original, pre-reserved seat. Our team members apologized for the error and attempted to de-escalate the situation. Ms. Mallory was rebooked on the next flight to New York's LaGuardia airport."

Another American Airlines spokesman, Joshua Freed, told the Daily News that "our team does not tolerate discrimination of any kind."