Pompeo arrived in Tokyo on Saturday for talks with Japanese officials before his trip to North Korea.
He will meet Japanese Prime Minister Shinzo Abe and Foreign Minister Taro Kono to discuss their North Korea policies before heading to Pyongyang on Sunday, second top on a trip that will also take him to South Korea and China.
Speaking on his plane on Friday, Pompeo said his mission was to “make sure that we understand what each side is truly trying to achieve … and how we can deliver against the commitments that were made” in Singapore when President Donald Trump and North Korean leader Kim Jong-un met earlier this year.
He said they would develop options, if not finalise, the location and timing of second Trump-Kim summit.
Trump and Kim made a vague “denuclearization” agreement their June summit but deadlocked over how to achieve it.
Pompeo’s last visit to North Korea failed to make progress with Pyongyang denouncing him for making “gangster-like demands”.
North Korea so far has suspended nuclear and missile tests, freed three American prisoners and dismantled parts of a missile engine facility and tunnel entrances at a nuclear test site. But it has not has not taken any steps to halt nuclear weapons or missile development.
Recently, Pompeo angered North Korea by insisting that international sanctions must remain in place until it gives up its nuclear weapons.
On Wednesday, he said there was unanimous support for this at last week’s UN General Assembly, even if Russia and China “had some ideas about how we might begin to think about a time when it would be appropriate to reduce them”.