WASHINGTON — Secretary of State Rex Tillerson says he is delegating his responsibilities at the end of the workday Tuesday to Deputy Secretary of State John Sullivan.

Speaking to reporters hours after being unceremoniously fired by President Donald Trump in a tweet, Tillerson says he will be formally stepping down from his post at the end of the month.

Tillerson is calling for an orderly transition to Mike Pompeo, the CIA director whom Trump has designated as Tillerson’s successor pending confirmation by the Senate. He encouraged State Department employees to remain focused on their jobs.

Tillerson also says his department “exceeded the expectations of almost everyone” on North Korea.

Trump was claiming credit for agreeing to a meeting with North Korea’s Kim Jong Un. But Tillerson suggested his own diplomatic work helped pave the way for that. He said on his watch, the U.S. won partners in an effort to use sanctions to force North Korea to scale back its nuclear program.

He said there was more to be done with regard to stabilizing Iraq, defeating Islamic militants, dealing with Russia and forging a way forward with China.

Tillerson added that “nothing is possible without allies and partners.”

The Associated Press wrote this story. The PBS NewsHour will update this story as it develops.