Under Armour Inc.'s Kevin Plank became the latest chief executive to quit President Donald Trump's council of U.S. business leaders, as membership on the panel has become enmeshed in the country's volatile politics after violent riots in Virginia over the weekend.

The move comes hours after Merck & Co.'s Kenneth Frazier also stepped down from the business council. Plank's departure is a sharp rebuke to Trump, after the Under Armor executive earlier this year came under fire for commenting that the president was a "real asset" for the country.

"Under Armour engages in innovation and sport, not politics," Plank said in a tweeted statement that referenced the company's aim to promote diversity and inclusion. Frazier said he quit "as a matter of personal conscience, I feel a responsibility to take a stand against intolerance and extremism."