President Donald Trump still intends to meet with North Korea's leader by the end of May, the White House said Friday, three days after the firing of Secretary of State Rex Tillerson.

The news came from a readout of Trump's phone call Friday with South Korean President Moon Jae-in.

"The two leaders agreed that concrete actions, not words, will be the key to achieving permanent denuclearization of the Korean Peninsula," the White House said, "and President Trump reiterated his intention to meet with North Korean leader Kim Jong Un by the end of May."

Trump rattled the international community and his own administration last week when he quickly accepted North Korea leader Kim Jong Un's invitation to meet. The planning for a potential meeting is happening as the State Department, which is already riddled with vacancies, is transitioning to a new secretary of State. The department also lacks a permanent ambassador to South Korea.

Experts have expressed skepticism that the meeting would take place, or that it would yield any results, and the White House has insisted that North Korea will have to meet specific conditions first.

According to the White House, Moon and Trump "expressed cautious optimism over recent developments and emphasized that a brighter future is available for North Korea, if it chooses the correct path."

Trump's decision to agree to a meeting with Kim came March 8, while Tillerson was in Africa tending to other diplomatic business. It was a dramatic reversal for the president, who had made threats against North Korea after the rogue nation's numerous missile launches. He also called Kim "Little Rocket Man."

Tillerson, who did not see eye-to-eye with the president on numerous issues, had pressed for diplomacy on North Korea, which Trump publicly mocked.

Trump fired Tillerson on Tuesday, and picked CIA Director Mike Pompeo as his replacement.