Several members have quit President Trump’s National Infrastructure Advisory Council, citing his response to the violence in Charlottesville, as well as “insufficient attention” to cybersecurity threats that face the United States.

Eight members left the group, three of which were holdovers from the Obama administration. This makes up a significant portion of the group, which is now left with 20 members, according to its website. The group advises the White House on cybersecurity, among other areas such as counterterrorism and border security.

“You have given insufficient attention to the growing threats to the cybersecurity of the critical systems upon which all Americans depend, including those impacting the systems supporting our democratic election process,” the group wrote in its resignation letter, which was recently obtained by NextGov.

Another topic at issue for the resigning members was how Trump handled the recent violence in Charlottesville, Va., with the letter going on to accuse the president of failing “to denounce intolerance and violence of hate groups.” Other factors they cited for the exit included Trump’s withdrawal from the Paris Climate Agreement and his criticism of the motives of the CEOs who recently quit his economic advisory councils, also in the wake of Charlottesville.

“In taking on this duty, I took an oath to support and defend the Constitution of the United States against all enemies, foreign and domestic,” the letter reads. “Today, that oath compels me to resign. The moral infrastructure of our nation is the foundation on which our physical infrastructure is built. The administration’s actions undermine that foundation.”

The resignation came a day prior to quarterly meetings held this past week by the U.S. Department of Homeland Security's National Infrastructure Advisory Council (NIAC) — meetings that continued as scheduled.

In May, Trump signed an executive order to bolster the government’s cybersecurity efforts and to protect critical infrastructure from cyberattacks. Trump has also called this issue a top priority. In the spring, the Trump administration also failed deliver a comprehensive cybersecurity plan that it had promised.

The resigning members emphasized in the letter that “public-private collaboration is vital for addressing gaps we face in security across all U.S. infrastructure sectors” and vowed to advance America’s ability to defend itself “through other means.”