A U.S. Foreign Service officer with nearly a decade of experience working for the State Department resigned Thursday in protest of President Donald Trump and his administration’s “toxic agenda.”

Chuck Park, whose most recent duties focused on trade development with British Columbia, explained his decision to step down in a searing opinion piece published Thursday in The Washington Post.

“I’m ashamed of how long it took me to make this decision,” Park wrote. “My excuse might be disappointing, if familiar to many of my colleagues: I let career perks silence my conscience. I let free housing, the countdown to a pension and the prestige of representing a powerful nation overseas distract me from ideals that once seemed so clear to me. I can’t do that anymore.”

Park condemned the Trump administration on several foreign policy actions, including its defense of Saudi Crown Prince Mohammed bin Salman in regard to journalist Jamal Khashoggi’s murder.

Though he was one of dozens of State Department workers to sign an internal dissent memo in 2017 objecting to Trump’s Muslim ban, Park said it wasn’t enough. He felt compelled to quit.

The University of Pennsylvania graduate also threw cold water on the existence of a so-called Deep State, the subject of a right-wing conspiracy theory that claims there’s a group of government officials working together to disrupt the Trump administration.

“Among my colleagues at the State Department, I have met neither the unsung hero nor the cunning villain of Deep State lore,” he wrote. “If the resistance does exist, it should be clear by this point that it has failed. Instead, I am part of the Complacent State.”

“Every day, we refuse visas based on administration priorities,” he said. “We recite administration talking points on border security, immigration and trade. We plan travel itineraries, book meetings and literally hold doors open for the appointees who push Trump’s toxic agenda around the world.”

Park suggested in his piece that the recent mass shooting in El Paso, Texas ― the city where his son was born ― was the last straw, noting the manifesto reportedly written by the gunman that echoed some of Trump’s anti-immigrant rhetoric.

“I can no longer justify ... my complicity in the actions of this administration,” said Park, a child of South Korean immigrants. “That’s why I choose to resign.”

Park told HuffPost in an email that he knows others in similar positions who have privately expressed concerns about the Trump administration. He said his piece in the Post was meant to be read as a warning more than a call to action to federal workers.

“Though we are keeping the metaphorical lights on, we are not the heroes that some make us out to be,” he told HuffPost. “The real ‘resistance’ must come from American voters in 2020.”

Park is one of several government officials to announce their resignation in response to Trump’s presidency and political agenda. Brett McGurk resigned his position as the U.S. envoy to the global anti-ISIS coalition in December in protest of Trump’s foreign policy decisions regarding Syria.

Read Park’s full opinion piece at The Washington Post.

This story has been updated with comment from Park.