On Tuesday, the former oil industry executive gave a short speech thanking his colleagues at the State Department and around the world, outlining foreign policy accomplishments and posing some questions for future leaders to think about.
The diplomat said he will pass along departmental powers to Deputy Secretary of State John Sullivan and will work to ensure a "smooth and orderly" transition to the next department head.
Tillerson outlined accomplishments, saying the department had "exceeded the expectations of almost everyone" with the "maximum pressure" campaign against North Korea. He also said some of the ceasefires negotiated in Syria had saved "thousands of lives."
Still, the US, China and Russia face challengers in their relationships and how to approach one another over the next 50 years, Tillerson said.
Tillerson's mostly textbook speech noted that for the first time in recent history the State Department and Defense Department had achieved a remarkable level of cooperation premised on the shared belief of putting diplomacy at the forefront of US foreign policy.