President Trump on Thursday voiced skepticism about his ability to stop his supporters from chanting “Send her back!” at his rallies, telling reporters outside the White House that he’s not sure whether it’s possible.

“I don’t know that you can stop people,” Trump said when asked whether he will stop his supporters if they begin that chant. “I don't know that you can. I mean, we’ll see what we can do. I’d prefer that they don’t. But if they do it, we’ll have to make a decision then.”

The exchange came shortly before he is set to headline a “Make America Great Again” rally in Cincinnati.

Last month, at a campaign rally in Greenville, N.C., the crowd responded to Trump’s attacks on Rep. Ilhan Omar (D-Minn.), who was born in Somalia, with chants of “Send her back! Send her back!”

The crowd’s response to Trump echoed the racist remarks he aimed at Omar and three other minority Democratic congresswomen he has accused of making hateful comments about the country, setting off a controversy that led the House to vote to formally rebuke him.

Trump had earlier tweeted that the four Democrats should “go back” to “the crime infested places from which they came.” All four congresswomen are U.S. citizens, and only Omar was not born in the United States.

Trump later distanced himself from the chant and falsely claimed that he had tried to stop it, even though he paused for 13 seconds in Greenville to allow the chant to continue.

On Thursday, when asked whether he expects his supporters in Cincinnati to repeat the chant, Trump told reporters, “I don’t know what’s going to happen.” He also took aim at the Democratic presidential contenders who took part in debates the past two nights in Detroit.

“I have no idea,” Trump said. “We have a great group of people. They love our country. They love the job we’re doing. And when they see the kind of people that want to represent us from the last two nights, that’s not what they want. I don’t know; I can’t tell you whether or not they’re going to do that chant. If they do the chant, we’ll have to see what happens.”

Asked Thursday whether he has a message for his supporters, Trump said, “I do have a message . . . You know what my message is? I love them. And I think they love me. I actually think they love me.”

Outside the arena where Trump’s rally was set to take place, supporters had mixed reactions when asked whether they planned to join in if the crowd broke out into chants of “Send her back!”

Some, like Shawn Meinhardt, a 50 year-old from Ohio, embraced the chant.

“I would have to say I agree with the chant because I’m ex-military,” he said. “Some of the things she says are so anti-Semitic it’s ridiculous. I have to be honest and say I’d probably join in if it was chanted tonight.”

Trump supporter Ken Barden insisted the crowd would be encouraged to adopt a new chant: “Vote her out.”

The 56 year-old, who traveled to Cincinnati from Missouri and planned to stand directly in front of the stage, acknowledged the last rally chant directed at Omar was “regrettable.”

“They are going to be shouting ‘Vote her out,’ and there will be no ‘Send her home,’” Barden said. “This is a democratic republic.”

Several rallygoers said they would steer clear of saying “Send her back,” even though they empathized with those who chanted it in Greenville.

“[Omar has] been very vocal about America and putting it down, so I think that people have reached a point where they’ve had enough,” said Andrea Shannon, 53. “I don’t think I would join in as I don’t agree with the ‘send her back’ sentiment, but I understand people’s frustration.”

Others commented on the religion of Omar, who is one of two Muslim women elected to the House last year.

“I wouldn’t join in with that chant,” said Tom Smith, a 65 year-old from Ohio. “She’s a naturalized citizen. But she doesn’t assimilate, and that’s the whole thing. I don’t think Omar has, and I don’t think she wants to. Islam is not a religion that conforms to anything. Islam wants you to conform to it.”

And some attendees maintained that the president had just been misunderstood. Eddie Decker, a 39-year-old Trump supporter, said, “I think the media got it sideways.”

“All he’s saying is that if you’re not happy with America, why be here?” Decker said. “I can understand where he’s coming from. He’s not racist. If you don’t love this country, then go home. I probably would join in with the chant. I’m not racist. . . . If anybody should love America, she should love what America has done for her.”

Omar, meanwhile, tweeted photos of herself Thursday with House Speaker Nancy Pelosi (D-Calif.) on a congressional delegation to Ghana. Omar is one of more than a dozen Congressional Black Caucus members who are on the trip.

Coinciding with the 400th anniversary of the arrival of the first enslaved Africans in America, the trip included meetings with Ghanaian lawmakers and a visit to the “Door of No Return,” through which millions of Africans passed before being shipped off and sold into slavery.

“They said ‘send her back’ but Speaker @SpeakerPelosi didn’t just make arrangements to send me back, she went back with me,” Omar tweeted. “So grateful for the honor to return to Mother Africa with the @TheBlackCaucus and commemorate The Year of Return!”

Hughes reported from Cincinnati. Ashley Parker contributed to this report.