Eight of cyber-security advisers have resigned, warning the President had “given insufficient attention to the growing threats” facing the US.
A quarter of the National Infrastructure Advisory Council’s 28 members quit with a joint letter in which they claimed Mr Trump “threatened the security of the homeland”.
They cited his response to white supremacist violence in , the country’s withdrawal from the on climate change, and the vulnerability of the US election process.
The panel is tasked with advising the US Homeland Security Department on cyber-security and the protection of infrastructure.
The eight departing members accused Trump’s administration of failing to be “adequately attentive to the pressing national security matters” or “responsive to sound advice received from experts”.
“Your actions have threatened the security of the homeland I took an oath to protect,” said their , obtained by IT news website .
The resignations come after Mr Trump following a flurry of resignations from chief executives over his response to the neo-Nazi rally in Virginia.
The President’s most controversial comments on the violence, in which he suggested left-wing activists were partly responsible for a white supremacist killing an anti-fascist protester, were made at a press conference on infrastructure reform.
“When asked about the horrific violence in Charlottesville, you failed to denounce the intolerance and violence of hate groups, instead offering false equivalences and attacking the motives of the CEOs who had resigned from their advisory roles in protest,” said the cyber-security experts’ resignation letter.
It added: “The moral infrastructure of our nation is the foundation on which our physical infrastructure is built.”
The advisers said the President had “given insufficient attention to the growing threats to the cyber-security of the critical systems upon which all Americans depend, including those impacting the systems supporting our democratic election process.”
Mr Trump has repeatedly downplayed and cast doubt on US intelligence officials’ conclusion that a Russian hacking campaign had attempted to subvert the 2016 presidential election.
World news in pictures World news in pictures
The resignation letter added: “Additionally, your decision to withdraw from the Paris Agreement, your intent to revoke flood-risk building standards, and your many other actions to ignore the pressing threat of climate change to our critical infrastructure also point to your disregard for the security of American communities.”
Three Obama-era White House officials were among the departing council members.
Former US chief data scientist DJ Patil, Office of Science and Technology Policy chief of staff Cristin Dorgelo, and Christy Goldfuss, managing director of the Environmental Quality Council, all confirmed their resignations on Twitter.
Members of the council, set up in 2001, are drawn from the private sector, government and academia.