CHARLOTTESVILLE, Va., Aug 14 (Reuters) - Merck's MRK.N chief executive resigned on Monday from a business panel led by Donald Trump, citing a need for leadership countering bigotry in a strong rebuke to the U.S. president over his response to a violent white nationalist rally in Virginia.

The departure of Kenneth Frazier from the president's American Manufacturing Council added to a storm of criticism of Trump over his handling of Saturday's violence in Charlottesville, in which a woman was killed when a man drove his car into a group of counter-protesters.

Democrats and Republicans have attacked the Republican president for waiting too long to address the violence, and for saying "many sides" were involved rather than explicitly condemning white-supremacist marchers widely seen as sparking the melee.

A 20-year-old man said to have harbored Nazi sympathies as a teenager was due in court on Monday to face charges he plowed his car into protesters opposing the white nationalists, killing Heather Heyer and injuring 19 people.

Frazier did not name Trump or criticize him directly in a statement posted on the pharmaceutical company's Twitter account, but the rebuke was implicit.

"America's leaders must honor our fundamental values by clearly rejecting expressions of hatred, bigotry and group supremacy," said Frazier, who is black.

Trump immediately hit back, referring to a longstanding gripe about expensive drugs. Now he had left the panel, Frazier would have more time to focus on lowering "ripoff" drug prices, Trump said in a Twitter post.

The outrage over Trump's reaction to the Charlottesville violence added to a litany of problems for the president.

Opponents have attacked him for his explosive rhetoric toward North Korea and he is publicly fuming with fellow Republicans in Congress over their failure to notch up any major legislative wins during his first six months in office.

Trump was specifically taken to task for comments on Saturday in which he denounced what he called "this egregious display of hatred, bigotry and violence on many sides."

Under pressure to take an unequivocal stand against right-wing extremists who occupy a loyal segment of Trump's political base, the administration sought to sharpen its message on Sunday.

The White House issued a statement insisting Trump was condemning "all forms of violence, bigotry and hatred, and of course that includes white supremacists, KKK, neo-Nazi, and all extremist groups." Vice President Mike Pence also denounced such groups on Sunday.

Trump's attorney general, Jeff Sessions, tried to defend the president over his reaction, appearing on a series of morning talk shows on Monday.

Asked about the president's words and lack of direct condemnation of white nationalist groups, Sessions defended Trump's statement and said he expected him to address the incident again later on Monday.

Trump was scheduled to meet with Sessions and FBI Director Christopher Wray on Monday morning to discuss the Charlottesville incident, the White House said in a statement.



BAIL HEARING

Authorities said Heyer, 32, was killed when James Alex Fields' car slammed into a crowd of anti-racism activists confronting neo-Nazis and Ku Klux Klan (KKK) sympathizers, capping a day of bloody street brawls between the two sides in the Virginia college town.

The bail hearing for Fields was set to unfold in Charlottesville as the U.S. Justice Department pressed its own federal hate-crime investigation of the incident.

Fields was being held on suspicion of second-degree murder, three counts of malicious wounding and a single count of leaving the scene of a fatal accident, authorities said.

More than 30 people were injured in separate incidents, and two state police officers died in the crash of their helicopter after assisting in efforts to quell the unrest.

The disturbances began with white nationalists converging to protest against plans to remove a statue of Confederate General Robert E. Lee, the commander of rebel forces during the U.S. Civil War.

The web hosting company GoDaddy said on Sunday it had given the Daily Stormer 24 hours to move its domain to another provider after the extremist web site posted an article denigrating Heyer. The Daily Stormer is a neo-Nazi, white-supremacist website associated with the alt-right movement.

Derek Weimer, a history teacher at Fields' high school in Kentucky, told Cincinnati television station WCPO-TV that he remembered Fields harboring "some very radical views on race" as a student and was "very infatuated with the Nazis, with Adolf Hitler."

The Army said Fields reported for basic military training in August 2015 but was "released from active duty due to a failure to meet training standards in December of 2015." An Army statement did not say how he failed to meet training standards. (Reporting by Ian Simpson in Charlottesville; Additional reporting by Susan Heavey in Washington; Writing by Steve Gorman and Frances kerry; Editing by Paul Tait and Bill Rigby) ((jon.herskovitz@thomsonreuters.com; +1 512 285-0178; Reuters Messaging: jon.herskovitz.thomsonreuters.com@reuters.net))