Director of U.S. National Intelligence James R. Clapper Jr., says he has submitted his letter of resignation, but plans to stay on until the end of the Obama administration. (Reuters)

Director of National Intelligence James R. Clapper Jr. said Thursday that he has submitted his letter of resignation to President Obama, cementing his long-declared plan to leave his job as the nation’s spy chief when a new president is sworn in.

“I submitted my letter of resignation last night, which felt pretty good,” Clapper said in testimony Thursday morning before the House Intelligence Committee. “I have 64 days left and I would have a hard time with my wife for anything past that.”

U.S. officials emphasized that Clapper’s resignation was unrelated to the election victory of Donald Trump, who has publicly dismissed the work of U.S. spy agencies on critical issues, including Russia’s interference in the election and Moscow’s involvement in the war in Syria.

Clapper began his career as a rifleman in the U.S. Marine Corps Reserve and went on to serve in a series of intelligence-related assignments over the past 50 years, culminating in his appointment as director of national intelligence in 2010.

The disclosure that Clapper has submitted his letter comes at a time of widespread apprehension among U.S. intelligence agencies over how they will be treated in a Trump administration. One of the leading candidates to serve as CIA director, former House Intelligence Committee Chairman Mike Rogers, was expelled from the Trump transition team this week as part of an internal purge.

Clapper has only hinted at his views of Trump, saying at a security conference in July that the divisive rhetoric of the presidential campaign had worried foreign allies. Asked how he responded to such concerns, Clapper said, “I tell them that I appreciate them sharing their concerns, that it is our process in the United States and hopefully it will all come out right.”

U.S. intelligence agencies have repeatedly been at odds with Trump. Clapper’s office released a statement in October that Russia was directly involved in a cyber campaign designed to disrupt the U.S. election, and that the operation was almost certainly approved by Russian President Vladimir Putin.

Trump has rejected those conclusions, saying during one of the presidential debates that it was just as likely that the election hacks were orchestrated by “somebody sitting on their bed that weighs 400 pounds.”