Outgoing Secretary of State Rex Tillerson didn't mention President Trump by name a single time as he bid farewell to the State Department Thursday, a week after Mr. Trump announced his firing on Twitter. But he did emphasize personal integrity and treating others kindly.

Addressing State Department employees Thursday afternoon, Tillerson said he hopes the department will "continue to treat each other with respect."

"This can be a very mean-spirited town," Tillerson said, to applause. "But you don't have to choose to participate in that."

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The possibility of Tillerson's ouster was a point of speculation for months, and came after a number of clashes with Mr. Trump. But the suddenness and execution of his ouster was shocking to many. Tillerson's departure also comes as the U.S. is looking to negotiate a meeting with North Korean leader Kim Jong Un -- in other words, a somewhat fragile time for foreign relations.

Mr. Trump has nominated CIA Director Mike Pompeo to take his place.

Outgoing U.S. Secretary of State Rex Tillerson waves to applauding State Department workers as he leaves the State Department for the last time in Washington on Thu., March 22, 2018. Reuters

Here are Tillerson's remarks:

"In these times, your continued diligence and devotion to the State Department's mission has never been more necessary. As you go about your duties, each of you carrying out your individual responsibilities as well as your collective duty, it is my hope that you will be guided by and test your actions each day by the values that we have spoke about over this past year. First, to value the safety and security of yourselves, your loved ones and your colleagues. Second, to maintain a commitment to accountability by first holding yourselves accountable so that you are able to hold others accountable. And that the positive environment of accountability is underpinned by honesty and integrity, in all that you do. Never lose sight of your most valuable asset, the most valuable asset you possess -- your personal integrity. Not one of you was gifted it -- you were born with it. It belongs to you, and always has and will belong to you and you alone. Only you can relinquish it or allow it to be compromised. Once you've done so, it is very, very hard to regain it. So guard it as the most precious thing you possess. And finally I hope you will continue to treat each other with respect, regardless of the job title, the station in life, or your role, everyone is important to the State Department. We're all just human beings trying to do our part. In closing I'd like to ask that each of you undertake to ensure one act of kindness each day towards another person. This can be a very mean-spirited town. "But you don't have to choose to participate in that. Each of us get to choose the person we want to be, and the way we want to be treated, and the way we will treat others. God bless you all, your loved ones, God bless America."