Merck CEO and chairman Kenneth Frazier, a Philadelphia native, resigned from President Trump's American Manufacturing Council on Monday over the president's muted response to the white nationalism that fueled a deadly rally Saturday in Charlottesville, Va. Frazier's exit starting a domino effect that ended with a total of three executives walking away in protest.

"America's leaders must honor our fundamental values by clearly rejecting expressions of hatred, bigotry, and group supremacy, which run counter to the American ideal that all people are created equal," Frazier said in a statement Monday morning. "As CEO of Merck and as a matter of personal conscience, I feel a responsibility to take a stand against intolerance and extremism."

Hours later, President Trump lashed out on Twitter at Frazier's decision, noting in all caps that the executive can now shift his focus to "LOWER RIPOFF DRUG PRICES."

Several hours later, the president tweeted, "@Merck Pharma is a leader in higher & higher drug prices while at the same time taking jobs out of the U.S. Bring jobs back & LOWER PRICES!"

Later into Monday evening, Trump sent a second tweet about Merck directed at Frazier.

Frazier, in December, said his company has a "restrained" approach to price increases, calling aggressive price increases a foolhardy move by the industry. In a company report published this year, Merck said it has a "long history of making our medicines and vaccines accessible and affordable through responsible pricing practices."

For 2016, the list price on its drugs rose by 9.6 percent on average while the net price, which more closely reflects what is paid by consumers, rose 5.5 percent, according to the report.

Former Philadelphia Mayor Michael Nutter came to Frazier's defense Monday afternoon, writing on Twitter that President Trump is not used to dealing with "strong Black Men" like Frazier.

Early Monday evening, Kevin Plank, the CEO of athletic wear manufacturer Under Armour, announced on Twitter he had also chosen to resign from Trump's manufacturing council. Plank said his company "engages in innovation and sports, not politics," and while the CEO did not specifically mention Trump or Charlottesville, he did say his company would focus on promoting "unity, diversity, and inclusion" through sports.

Hours later, Intel CEO Brian Krzanich became the third executive to to resign from the president's manufacturing council. In a blog post on the Intel website, Krzanich said he was pulling out to bring attention to the "serious harm our divided political climate is causing to critical issues, including the serious need to address the decline of American manufacturing."

"I have already made clear my abhorrence at the recent hate-spawned violence in Charlottesville, and earlier today I called on all leaders to condemn the white supremacists and their ilk who marched and committed violence," Krzanich said.

So far, Trump has chosen not to comment on the resignations of Plank and Krazanich.

After Saturday's deadly rally in Charlottesville, many critics, including Republicans, have criticized President Trump for not chastising the hundreds of white nationalists, neo-Nazis, and Ku Klux Klan members whose views fueled the violence that left a counterprotester dead and indirectly resulted in the helicopter crash that killed two state troopers on protest duty.

"We condemn in the strongest possible terms this egregious display of hatred, bigotry, and violence on many sides. On many sides," Trump said during a Saturday news conference from his golf club in Bedminster, N.J.

On Monday, Trump clarified his remarks in a prepared statement he read at the White House, saying those who spread violence in the name of bigotry "strike at the very core of America."

"Racism is evil, and those who cause violence in its name are criminals and thugs, including the KKK, neo-Nazis, white supremacists and other hate groups that are repugnant to everything we hold dear as Americans," Trump said.

Frazier, who had been the only black member of the presidential manufacturing council, came from humble roots in North Philadelphia to lead the major drug manufacturer. He is the son of a Philadelphia janitor and graduated from Northeast High School.

"Yes, by the accident of geography, my father's house was at 18th and Diamond Streets," Frazier said in an interview for a 2010 profile, when he was first named to lead Merck & Co. Inc, in Kenilworth, N.J. "But the standards of my father's house were universal in that he believed in hard work and the importance of education."

A Penn State graduate, Frazier served as the chairman of a Penn State board of trustees that hired Louis Freeh to lead the investigation of a pedophilia scandal involving former assistant football coach Jerry Sandusky. The commission found that Penn State administrators failed to take action to stop Sandusky.

Trump's American Manufacturing Council is composed of more than two dozen CEOs and has the goal of creating recommendations on growing the country's manufacturing sector. Tesla Inc. CEO Elon Musk was also a member of the council, but withdrew in June after Trump announced he was pulling the country of our the Paris climate accord.

Also on the council is Denise Morrison, chief executive of Campbell Soup, which is based in Camden. Morrison will remain on the council.

"The reprehensible scenes of bigotry and hatred on display in Charlottesville over the weekend have no place in our society. Not simply because of the violence, but because the racist ideology at the center of the protests is wrong and must be condemned in no uncertain terms," the company said in a statement. "We believe it continues to be important for Campbell to have a voice and provide input on matters that will affect our industry, our company and our employees in support of growth. Therefore, Ms. Morrison will remain on the President's Manufacturing Jobs Initiative."

Republican leaders, including House Speaker Paul Ryan and Republican National Committee Chairwoman Ronna Romney McDaniel, strongly denounced white supremacy and called the views behind the gathering "repugnant."

"Their tiki torches may be fueled by citronella, but their ideas are fueled by hate, and have no place in civil society," said Sen. Orin Hatch (R., Utah). "We should call evil by its name. My brother didn't give his life fighting Hitler for Nazi ideas to go unchallenged here at home."

On Sunday, a White House spokesperson clarified Trump's comments in a statement that read, "Of course" the president condemns violence by "white supremacists, KKK, Neo-Nazi, and all extremist groups." On Sunday night, Vice President Pence defended Trump's comments and called out the media for reporting on the widespread criticism of Trump's remarks.

"I take issue with the fact that many in the national media spent more time criticizing the president's words than they did criticizing those that perpetuated the violence to begin with," Pence said during a news conference in Cartagena, Colombia, according to a White House pool report.