TOKYO/SEOUL -- U.S. and North Korean government officials are working toward the summit between Donald Trump and Kim Jong Un in Singapore on June 12. But what kind of results the historic summit might yield remain uncertain since the U.S. and North Korea have different ideas regarding how and when North Korea will give up its nuclear weapons. Washington has spoken of a unilateral disarmament, while Pyongyang has talked about denuclearizing little by little as the U.S. makes economic concessions. 

Here are answers to five common questions regarding the highly anticipated event.

Where and how will the summit take place?

The White House has said the summit will take place at the Capella Hotel on Singapore's Sentosa Island. It is a 112-room, five-star hotel with colonial architecture dating from the 1880s. But Trump is reportedly staying at the Shangri-La, another luxury hotel, while the U.S. and North Korean delegations will be scattered across several hotels, including the Shangri-La. This means the substantive negotiations may take place somewhere other than the Capella Hotel.

The summit is scheduled to start at 9 a.m., according to the White House. Trump is expected to be given key talking points, but few expect him to stick to the script.

Trump's penchant for theatrics also means there could be surprises in store, such as the president suddenly walking out of the negotiations and then returning.

The U.S. president has already called off the planned summit once, on May 24. But by May 26 he was talking as though it might be back on, welcoming positive words from Pyongyang. After a meeting with Kim Jong Un's top aide in Washington on June 1, Trump confirmed the summit is back on as originally planned. Both sides are working on a framework that would allow Trump and Kim to go home claiming victory.

With Trump often changing his mind, some experts say they won't believe that a summit will take place until they see it.

South Korean President Moon Jae-in could also participate. On May 27, Moon expressed his desire to build on the momentum for dialogue, by following up the Trump-Kim summit with a three-way summit and declaring a formal end to the Korean War.

The two Koreas remain in a state of armistice after the 1950-53 war. U.S.-led U.N. forces and a Chinese volunteer army took sides in the fighting. Millions died.

Why do Trump and Kim want a summit now?

Engulfed in scandals, Trump might be eyeing a summit as a way to bolster his political support at home. His administration has long been dogged by a special counsel investigation that is looking into Russian involvement in the 2016 U.S. presidential election, which resulted in Trump winning by a count of delegates, not votes. Trump has also changed his story on the matter of hush money paid to an adult film actress who alleges she and Trump had an affair.

Trump is "in need of a political victory in order to help strengthen his political position," said Jannuzi, the president of the Mansfield Foundation, a non-governmental group based in Washington that promotes U.S.-Asia relations. "He is eager to remind the country that he is capable of accomplishing great things. I'm sure that he wants very much a chance to celebrate some progress, especially on an issue that has been so hard for 70 years and where he can make history by becoming the first sitting U.S. president to ever meet the leader of North Korea."

Kim wants crippling international sanctions lifted.

"Kim Jong Un's top priority is to avoid isolation and suffering led by the U.S.'s 'maximum pressure' strategy," said Jin Chang-soo, president of the Sejong Institute, in Seongnam, a satellite city south of Seoul.

Jin said Kim's two meetings this year with Chinese President Xi Jinping were part of the North Korean leader's strategy to ease the economic pressure squeezing his country.

But Kim wants more than economic relief. "He is also expected to demand a guarantee for the security of his regime," Jin said. Such a guarantee would be difficult to keep.

What would a successful outcome look like?

One strong possibility is that the two sides sign a general statement calling for denuclearization of the Korean Peninsula and a formal end to the Korean War.

Initially there were hopes from the U.S. that North Korea would immediately give up its nuclear weapons. But Pyongyang has strongly resisted this idea and the U.S. has backtracked, with Trump now saying denuclearization will take time and that he is open to meeting with Kim more than once to settle the issue.

"It's a process," Trump said. "We're not going to go in and sign something on June 12, and we never were. We're going to start a process. And I told them today, 'Take your time. We can go fast. We can go slowly.'"

Still, from the U.S. point of view, for any commitment to be credible, Washington and Pyongyang need to take at least the first few steps toward creating a road map to denuclearization and peace.

For Kim to consider the summit successful, he would need to win diplomatic, economic and military gifts, said Park Won-gon, a professor of international relations at Handong Global University, in the southeast city of Pohang.

"First of all, Kim may want to establish diplomatic relations with the U.S.," Park said. "Economic benefits are also important to the country. And finally, I think this is the most important, North Korea wants Washington to do something on the military side." U.S.-South Korean military drills as well as U.S. military installations in South Korea have long irritated North Korea.

Park also said Pyongyang does not want to have to send its nuclear warheads outside the country and feels that any such capitulation on its part would be a failure.

U.S. President Donald Trump and North Korean leader Kim Jong Un   © AP

Surely the summit has other stakeholders. Who are they and how are they reacting?

Washington-Pyongyang exchanges are being closely watched by North Korea's neighbors, starting with China, which has been the Kim regime's security guarantor.

Beijing has always called for stability on the Korean Peninsula, fearing a reignition of the Korean War would send waves of refugees into China. But China's support for denuclearization is about much more than peace and stability.

"As long as North Korea has nuclear weapons, America will remain on guard and hostile to North Korea," Jannuzi said. "America will have an excuse to strengthen [its military presence] in Northeast Asia." This is anathema to China.

While the U.S. backs a unified Korea that is peaceful and a U.S. ally, China prefers either a divided Korea, with the North serving as a buffer, or a unified Korea that is neutral or even pro-China. "I do not think China supports South Korea swallowing North Korea," Jannuzi said. "China will try to defend North Korean sovereignty."

South Korea has a lot at stake and is pushing hard for rapprochement. President Moon Jae-in might even end up joining Trump and Kim.

Japan also wants to be heard. It is insisting on "the complete, verifiable and irreversible" dismantlement of North Korea's nuclear weapons. In addition, it is calling for the summit participants to take up the threats Japan faces from North Korea's intermediate-range ballistic missiles. Tokyo also wants a final resolution to decades-old cases of Japanese being spirited away to North Korea. Many of the abductees remain unaccounted for.

What can be expected after the summit?

Even if a joint declaration is made, the words would only mark the beginning of a long journey toward real peace. First, the sides would have to come up with a road map of phased reciprocal actions. This would take months.

The two leaders might also schedule a peace conference to which Moon and Xi would be invited and where the four parties would discuss how to formally end the Korean War.

China fought in that war on the North's behalf.

Officials from both sides will have to work to keep the diplomatic process on track. But similar efforts in the past have never produced durable peace.

"It's going to be a long and difficult process," Jannuzi said, "and there will be many opportunities for failure."