NEW YORK -- NBC was not responding to a challenge by talk-show host Lawrence O'Donnell to disclose whether Donald Trump will return next fall with "The Celebrity Apprentice."

"NBC has created a monster and it is called Donald Trump," O'Donnell said in a blistering 15-minute rant on Wednesday's edition of his show, "The Last Word," which airs on MSNBC, a sister network of NBC.

"NBC can no longer stand idly by, not for one more day," he said.

If a deal is in place for another "Apprentice" season, Trump's attention-grabbing flirtation with a presidential bid is nothing more than a publicity stunt, O'Donnell declared.

"If Donald Trump has committed to do ('Celebrity Apprentice'), he is obviously not running for president," O'Donnell said, "and all of this, every bit of it, is as fake as Donald's reality show."

NBC, which will formally announce its 2011-12 season schedule on May 16, must already know if more "Celebrity Apprentice" is in the cards, O'Donnell said. He insisted that NBC settle the question right away and avoid being part of what he called Trump's "campaign to legitimize hatred and racism."

WATCH:

NBC declined to comment Thursday.

"I wouldn't dignify Lawrence O'Donnell's ridiculous statements by even providing a response," said Michael Cohen, an executive with the Trump Organization and a Trump spokesman.

O'Donnell's latest blast at Trump, a not-infrequent target, came hours after the White House released President Barack Obama's long-form birth certificate from Hawaii, debunking persistent claims that Obama was born in Africa.

The so-called "birther" controversy has dominated the early stage of the 2012 GOP nominating contest, with Trump leading the charge. Then, on Wednesday, he boasted of having "played such a big role" in prodding Obama to release the document.

During his recent media blitz, Trump has also suggested, without providing evidence, that Obama was a mediocre student who did not deserve to be admitted to the Ivy League universities he attended.

Trump's quasi-political campaign has dovetailed with the current season of "Celebrity Apprentice," which has drawn a robust audience hovering around 8.2 million viewers in its first eight weeks.

On Wednesday, Trump repeated to reporters his intention to reveal his presidential plans after the show's season conclusion. While plugging the May 22 finale, Trump explained, "When the show is over, I will then be free to announce."

But O'Donnell disputed Trump's rationale, saying he could continue on the show even after announcing his plans, without NBC being forced to supply equal airtime to other candidates. Trump would not officially become a candidate until filing the legally required documents, O'Donnell said.

"He could wait for weeks or months to file those papers after simply saying he's going to run for president," O'Donnell said. "Trump is now hiding behind NBC when asked the single most important question in front of him: Are you going to run for president? And NBC is allowing him to hide behind NBC."