Those details could prove major sticking points in the future while North Korea is believed to maintain a nuclear arsenal capable of threatening the U.S mainland. "A lot of work", Mr. Trump said of the summit.
The Singapore agreement does not detail plans for North Korea to demolish a missile engine testing site, a concession Trump said he'd won, or Trump's promise to end military exercises in the South while negotiations between the USA and the North continue.
Japan's defence chief said on Wednesday that the USA military presence in South Korea and joint military exercises were "vital" for East Asian security. They said it couldn't be done, they scoffed.
A document signed by President Donald Trump and North Korea's leader Kim Jong Un is seen in Singapore in this picture released on June 12, 2018 by North Korea's Korean Central News Agency. -South Korea joint missile drill aimed to counter North Korea's intercontinental ballistic missile test in East Coast, South Korea, July 5, 2017. There are also joint US-Japanese drills each year.
In the U.S., supporters of President Trump welcomed the outcomes of the summit as a historic breakthrough.
China has confirmed that Pompeo will visit Beijing on Thursday. The Chinese Foreign Ministry has praised the "important progress" made at the Singapore summit to begin resolving the Korean peninsula's problems. That was the personal assessment made by Trump, after the summit.
In Pyongyang, North Korean state media heralded claims of a victorious meeting with the US president; photos of him standing side-by-side with Trump on the world stage were splashed across newspapers.
But with no clear signs of how or when the process will unfold, others have been more cautious about the summit's implications.
One showed a smiling Kim shaking hands with Trump's hawkish National Security Advisor John Bolton, who has previously advocated military action against the North, which in turn has referred to him as "human scum".
South Korean President Moon Jae-in meanwhile hailed the outcome of the Singapore Summit, saying the "historic event" had ended the last Cold War conflict.
However, there was no mention of the previous United States aim of "complete, verifiable and irreversible denuclearization" from Pyongyang.
But Panetta, who previously worked for President Barack Obama, said there are a "huge number of issues" that will actually involve the denuclearization of North Korea, which owns an estimated 20 to 60 nuclear weapons with about 141 sites that can produce them. Typically, arms-control deals are verified by trained experts inspecting military and nuclear facilities. It said that he had also agreed to "step by step" denuclearization, rather than the rapid and irreversible process the administration said it was demanding.
The KCNA report - which was also carried by the Rodong Sinmun, official newspaper of the ruling Workers' Party - also claimed that the president pledged to suspend military drills with South Korea, and lift sanctions on the North.
In Pyongyang, commuters crowded round the spread of images the first they had seen of the summit, for majority.
Several topics were discussed Tuesday during Trump and Kim's summit, including the "complete denuclearization of the Korean Peninsula."
And, for the time being at least, North Koreans are sticking to their normal slogans of support and loyalty when asked how they feel about what could be some very momentous changes on the horizon.