The leader of the Navy's Pacific Fleet has announced that he plans to retire after learning that he won't be nominated to succeed his boss as head of Pacific Command.

Adm. Scott Swift, head of the Pacific Fleet, will not replace Adm. Harry Harris as the top officer in the Pacific. Swift said in a statement that he had been informed by Chief of Naval Operations Adm. John Richardson that he would not be moving up.

"In keeping with tradition and in loyalty to the Navy, I have submitted my request to retire," Swift said in a statement Monday evening. "I do so with great appreciation and gratitude for the honor of having served so many Sailors and their families for what will be 40 years in January."

Harris, as head of Pacific Command, is in charge of all military operations in that area. Swift, as Pacific Fleet, oversees the naval component of Pacific Command.

Swift's announcement comes amid two major fleetwide investigations into training and readiness conditions in the Pacific Fleet after the collisions of the destroyers USS Fitzgerald and USS John S. McCain. The separate collisions this summer cost the lives of 17 sailors total. The Navy has since removed two admirals, along with other senior leaders over the collisions and the problems leading up to them.

Swift's statement does not reference the investigations.

"Submitting this request [to retire] now is done with an abundance of respect and admiration for the CNO and his leadership, as well as for the Chairman and Secretary of Defense as both of them face the challenge of selecting someone to step into the leadership role Admiral Harris has filled with such distinction over the last three years," Swift added.

Swift has not requested a retirement date, citing there is much work to be done in the Pacific.

"Whether my timeline of remaining service is six weeks or six months, I will fill that time with the energy of an Ensign and the wisdom drawn from the 140,000 Sailors who report for duty every morning in the Pacific Fleet," he said.

Harris and Swift have both held their respective positions since May 2015. The Pacific Fleet is headquartered out of Pearl Harbor, Hawaii.