Amid the shakeout from President Donald Trump’s statements on the violence erupting in protests in Charlottesville, Va., Merck & Co. chairman and CEO Kenneth Frazier said he’s leaving the President’s American Manufacturing Council.

Kenneth Frazier

Frazier said in a statement posted on Twitter early Monday morning, “I am resigning from the President’s American Manufacturing Council. Our country’s strength stems from its diversity … 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.

“As CEO of Merck and as a matter of personal conscience, I feel a responsibility to take a stand against intolerance and extremism.”

Trump has received criticism for not citing hate organizations in his statements condemning violence at a demonstration by white supremacist groups Saturday in Charlottesville, where a car ran over counter-protestors, killing a woman and injuring 19 others.

Less than an hour after Frazier’s tweet, Trump fired back on Twitter. “Now that Ken Frazier of Merck Pharma has resigned from President’s Manufacturing Council, he will have more time to LOWER RIPOFF DRUG PRICES!,” the president’s tweet read.

Later on Monday, Trump singled out racist groups by name in denouncing the clashes in Charlottesville, which claimed another two victims when a police helicopter crashed while surveilling the protests.