Atlanta CNN  — 

Donald Trump slammed GOP leaders on Wednesday for not lining up behind him, implying that he’s willing to go forward without their help.

“We have to have our Republicans either stick together or let me just do it by myself. I’ll do very well. I’m going to do very well. OK? I’m going to do very well. A lot of people thought I should do that anyway, but I’ll just do it very nicely by myself,” Trump said, though he did not elaborate on what doing it “by myself” would mean.

The presumptive Republican presidential nominee also accused his party’s leaders of being weak and told them to “please be quiet.”

“You know the Republicans, honestly folks, our leaders, our leaders have to get tougher,” Trump said during a rally in Atlanta. “Our leaders have to get a lot tougher. And be quiet. Just please be quiet. Don’t talk. Please be quiet. Just be quiet to the leaders because they have to get tougher, they have to get sharper, they have to get smarter.”

READ: Obama goes on anti-Trump tirade

Trump’s biting words for Republican leaders appeared to be a response to the deluge of criticism Trump has faced in recent weeks over his comments that a federal judge was biased against him because of his Mexican heritage and, most recently, House Speaker Paul Ryan’s rebuke of Trump’s proposed ban on Muslim immigration.

The criticism comes as Democrats have unified behind presumptive Democratic nominee Hillary Clinton and in the wake of a scathing anti-Trump speech by President Barack Obama, who issued an extraordinary condemnation of Trump on Tuesday.

Trump has sought to unify Republicans around his candidacy since clinching the party’s nomination in early May, but the billionaire businessman has grown frustrated in recent weeks with the pace of that coalescing – and the heavy fire he sustained from his own party amid his racial comments about the judge.

Ryan spokeswoman AshLee Strong declined to respond to Trump, instead pointing to Ryan’s remarks during a Tuesday news conference, during which Ryan reasserted that he does not “think a Muslim ban is in our country’s interest” nor “reflective of our principles.”

Ryan previously called Trump’s remarks about Judge Gonzalo Curiel “the textbook definition of a racist comment.”

RNC Chairman Reince Priebus’ office did not immediately respond to a request for comment.