Key question for summit: Where?

South optimistic about progress on denuclearization.

The United States and North Korea have been negotiating with “will and sincerity” over the details of the planned talks between President Donald Trump and the North’s leader, Kim Jong Un, President Moon Jae-in of South Korea said Wednesday.

Trump said Monday that U.S. officials had been talking directly with the North Koreans to prepare for his meeting with Kim, which he said would probably take place in May or early June. Moon said the two sides were discussing where to hold the meeting, among other issues.

“I hear that the United States and North Korea are preparing for the summit with both will and sincerity, holding detailed negotiations over the time, venue and agenda,” Moon’s office quoted him as saying Wednesday, during a meeting with officials preparing for his own talks with Kim on April 27.

“I am expecting the North Korea-United States summit to produce significant steps toward denuclearizing the Korean Peninsula and establishing permanent peace here,” Moon said.

Both Moon and Trump hope to persuade Kim to dismantle Pyongyang’s nuclear weapons program, which made dramatic advances last year even as the U.S. and North Korean leaders exchanged belligerent threats. Kim abruptly changed tack in January with diplomatic overtures, first to South Korea and later to Trump, who stunned the world by abruptly agreeing to talk directly to Kim.

South Korean and U.S. officials have said that the North expressed willingness to discuss denuclearizing. But it is unclear what Kim would want in return and whether Washington would meet his demands.

No sitting U.S. president has ever met with a North Korean leader. The two countries do not have diplomatic relations, which has led to complicated logistical issues around the summit meeting — starting with where it will be held.

It is unclear whether Kim would be daring enough to visit Washington, which North Korea has for decades accused of plotting to invade it. And Kim’s private jets are said to lack the fuel capacity for a nonstop flight to Washington from Pyongyang.

The idea of a summit meeting in Pyongyang makes some U.S. officials cringe, envisioning how North Korean propagandists would depict it as Trump paying homage to Kim. Some officials have also expressed reluctance to hold the talks in South Korea or at Panmunjom, the “truce village” on the inter-Korean border where Kim and Moon will hold their talks; the U.S. officials said they would prefer a neutral site that did not highlight the South’s role in facilitating the talks.

News reports in South Korea and the United States have mentioned Geneva and the Mongolian capital, Ulaanbaatar, as possible venues.

North Korea, as it has in the past, insists on a “phased” and “synchronized” implementation of any denuclearization deal. According to former South Korean officials who have dealt with the North, it fears that any deal it signs with Washington could come to an end after a change in U.S. administrations.