David Shulkin on Wednesday penned an op-ed following his ouster as Veterans Affairs (VA) secretary, railing against the "toxic" and "chaotic" environment in Washington and describing a "brutal power struggle" at the VA.

"As I prepare to leave government, I am struck by a recurring thought: It should not be this hard to serve your country," he wrote in the piece published in The New York Times.

Shulkin wrote about his accomplishments during his time at the VA and said it has been his "greatest professional honor" to serve the country's military veterans.

He said he fought during his time at the department to stand up "for this great department and all that it embodies."

"In recent months, though, the environment in Washington has turned so toxic, chaotic, disrespectful and subversive that it became impossible for me to accomplish the important work that our veterans need and deserve," he wrote.

"I can assure you that I will continue to speak out against those who seek to harm the V.A. by putting their personal agendas in front of the well-being of our veterans," he said.

He specifically blamed his opposition to privatizing health care at the VA for his ouster, saying "some political appointees" within the administration are "choosing to promote their agendas instead of what's best for veterans."

Shulkin added that he came to Washington understanding the city can by "ugly." He said he figured he could "avoid all of the ugliness by staying true to my values."

"I have been falsely accused of things by people who wanted me out of the way. But despite these politically-based attacks on me and my family's character, I am proud of my record and know that I acted with the utmost integrity. Unfortunately, none of that mattered," he wrote.

The op-ed comes after President Trump said Wednesday he was removing Shulkin and tapping Adm. Ronny Jackson, the White House physician, as his replacement, ending weeks of uncertainty at the embattled agency.

Trump announced the decision on Twitter, a move that caps off a stunning fall for Shulkin, who had once been among Trump's favorite Cabinet secretaries.

Shulkin's ouster adds to the shake-up in the Trump administration that has already resulted in the departures of the president's secretary of State, his top economic aide and his second national security adviser.

Shulkin had been in the hot seat for months over a scathing report accusing him of misusing taxpayer dollars.