U.S. Secretary of State Mike Pompeo is heading back to North Korea for another round of talks aimed at getting Kim Jong Un to give up nuclear weapons.

State Department spokeswoman Heather Nauert told reporters on Tuesday that Pompeo will meet with Kim on Sunday, following a daylong visit to Japan.

This will be Pompeo's fourth visit to North Korea since he became secretary of state. He made an earlier trip there, in April, when he was director of the CIA.

"Obviously these conversations are going in the right direction, and we feel confident enough to hop on a plane to head there," Nauert said.

President Donald Trump and Kim agreed to denuclearization only in vague terms at their summit in Singapore, the first meeting between leaders of the U.S. and North Korea.

Since then, North Korea has suspended missile testing and has taken some steps to dismantle facilities associated with its nuclear program, but it has not halted weapons development.

North Korea says it first wants relief from punishing international sanctions. U.S. officials have said the sanctions will remain in place until North Korea has "fully" and "verifiably" denuclearized.

Asked about sanctions, Nauert told reporters, "Our policy has not changed."

The meeting between Pompeo and Kim may also chart a possible second meeting between the two leaders. At a campaign rally on Saturday, Trump seemed to signal he was open to the prospect, when he spoke about the "beautiful letters" he had received from the North Korean leader. "We fell in love," he said.

Nauert said Trump's effusive comments were a positive sign for diplomacy. "I think if our leaders have relatively friendly relations, that that's a good thing," she said. "That that can only help us to achieve our final goal."