SEOUL, South Korea — Kim Jong-un, North Korea’s leader, plans to formally announce his willingness to denuclearize his country when he meets with President Moon Jae-in of South Korea this month, an official from the South said on Tuesday.

The statement is expected to be part of a joint declaration that the two leaders will adopt when they meet on April 27, said Mr. Moon’s chief of staff, Im Jong-seok. Negotiators from both Koreas have agreed on a rough framework for the joint declaration, he said.

They are still discussing other aspects of the joint statement, such as whether the two Koreas would commit to holding summit meetings on a regular basis, Mr. Im said. South Korea is also trying to convince North Korea that Mr. Moon and Mr. Kim should hold a joint news conference at the end of their meeting in Panmunjom, the so-called truce village on the inter-Korean border.

If necessary, Mr. Moon’s national security adviser, Chung Eui-yong, and his spy chief, Suh Hoon, will visit the North Korean capital, Pyongyang, again to resolve any significant issues before the summit meeting, Mr. Im said.