Washington — A majority of the artists who were announced as performers for what's being billed as a Great American State Fair amid President Trump's push for a major American birthday bash this summer in Washington, D.C., dropped out of their appearances shortly after an initial lineup was released. 

On Wednesday, Freedom 250 announced the initial set of artists lined up to perform. 

Mr. Trump said Saturday that he is considering replacing the event with what he called an "AMERICA IS BACK Rally," where he would "give a major speech, rallying the Country forward." He said he was ordering representatives to look into the feasibility of hosting such an event on short notice, and said that it would be a "Wild and Beautiful Celebration of America." 

Who has pulled out of the America 250 concert series? 

Morris Day of Morris Day and The Time said he won't be performing, contrary to the advertisement. "It's A No For Me," Morris' official Facebook account posted. 

Young MC, another artist advertised to perform, also said he won't be there. "I HAVE INFORMED MY AGENTS THAT I WILL NOT BE PERFORMING AT THE FREEDOM 250 EVENT," he posted on Facebook. "The artists were never told about any political involvement with the event. And despite the claims by the organizers that the event is non-partisan, SPIN magazine describes it as Trump-backed. I hope to perform in D.C. in the near future at an event that is not so politically charged."

The Commodores, also originally announced as performers, said on social media Thursday the group "will not be performing at the Great American State Fair."

"Our music has always been our voice and we choose not to publicly affiliate with any single political party," the statement said. "We support the betterment of all Americans."

Country singer Martina McBride announced on social media she will not perform. She wrote that she initially signed on because she was told the event would be nonpartisan, which "turned out to be misleading."

"I asked lots of questions and was assured this was a nonpartisan event that was meant to celebrate ALL 50 states," McBride wrote Thursday. "Yesterday things started changing and what we were told is, in fact, not what is happening."

Bret Michaels, of the band Poison, said on social media that he won't be there.

"Unfortunately, what was presented to us as a celebration of our country has evolved into something much more divisive than what I agreed to be a part of," he said. "Concerns have also been raised regarding the safety of my fans, band, crew, family and myself, including threats that are completely unfounded and unforgivable."

Who is still set to perform at the Freedom 250 concert series?  

Although half of the front-facing Milli Vanilli pop duo, Rob Pilatus, died in 1998, Fab Morvan, the other half of the duo, said he'll be performing. 

"Despite any rumors out there, I will be performing at The Great American State Fair in Washington, D.C. at the National Mall on June 26th, as a part of The I Love The 90's Tour," Morvan said in a statement to CBS News. "I am here to entertain and unite people, not divide them. Let's celebrate life & music and take a trip down memory lane. I feel honored to be a part of the Great American State Fair as it will celebrate the 250 Year Anniversary of America with so many other accomplished artists. Looking forward to reconnecting with you across the USA this summer and to finally sing Milli Vanilli songs live in person!"

Vanilla Ice, who is also part of the initial lineup, still plans to perform. "Vanilla Ice is contracted and will perform at the Great American Fair at the National Mall on Friday, June 26," his management agency told CBS News in an email. "He is proud to help celebrate America's 250th Anniversary!  Everyone is welcome to attend and celebrate USA's Birthday and our Freedom!" 

Others announced as performing at the Great American State Fair, a 16-day exposition taking place on the National Mall from June 25 through July 10, include C+C Music Factory and Flo Rida. CBS News has reached out to each artist advertised in the concert series to confirm their attendance. 

In a lengthy video posted to C+C Music Factory's Instagram page, band member Freedom Williams said that although he does not support Mr. Trump, he still plans to perform at the event. 

Freedom 250 said the initiative is nonpartisan, and should be treated as such. 

"Freedom 250 is a nonpartisan 501(c)(3) dedicated to uniting Americans around the nation's 250th anniversary," Freedom 250 spokesperson Rachel Reisner said. "Freedom 250 is focused on our signature celebrations and events that honor our history and engage all Americans — welcoming all who share our goal of commemorating this milestone in a way that uplifts and unites America." 

Mr. Trump has expanded on many of the 250th celebrations, although they were in the works before he became president.  

The Great American State Fair, according to Freedom 250, will feature all states and territories in a world fair-style celebration, including exhibits, showcases and cultural programming from the U.S. Capitol to the Washington Monument. Mainstage musical performances are expected every Thursday, Friday and Saturday night.