We welcome the efforts to open communications between the United States and North Korea facilitated by the diplomatic efforts of South Korea. We also recognize that one meeting - even a summit - cannot be expected to produce an immediate solution to the decades-old North Korean nuclear problem. This is just the beginning of a long process that will require persistence and patience to succeed.
Current circumstances could open the door to bringing about goals the key participants have said they wish to achieve. North Korea's leadership appears to wants a more secure and productive relationship with its neighbors and with the broader global community, especially the United States.
South Korea wants a stable and peaceful relationship with its northern neighbor that offers opportunities for development of the peninsula. The United States - and the rest of the international community - needs to see an end to North Korea's experiment with nuclear weapons and intercontinental delivery vehicles.
And China seeks a Korean Peninsula on its border functioning in a way that produces stability and confidence rather than uncertainty and potential conflict.
What can this summit achieve?
First and foremost, it must produce an agreed-upon statement committing the parties not only to a permanent end to hostilities but to the complete, irreversible, full and verifiable denuclearization of the peninsula. Those who see this as a measure to be taken in one leap must also see the hard reality. As Trump has noted, steps and stages may be the only secure and permanent way to achieve that main goal.
Second, a freeze in missile and nuclear-weapons testing is clearly needed, certainly for as long as conversations continue on the main goals of peace and denuclearization. The United States has shown it is prepared to demonstrate that its regular joint exercises with South Korea are defensive in nature, do not envision the use of nuclear weapons and are not an attempt to decapitate the North Korean leadership. It is critical that the summit yield a precise understanding of these first reciprocal steps to avoid misunderstandings such as the confusion last month over the presence of American B-52 bombers in the area.
Third, it is necessary to begin moving down the more difficult road of eliminating the production of fissile material for weapons use. North Korea should reaffirm its September 2005 commitment to the Six-Party agreement by abandoning all nuclear weapons and existing nuclear programs and returning, at an early date, to the Treaty on the Non-Proliferation of Nuclear Weapons, and to safeguards established by the International Atomic Energy Agency.
For its part, the United States should reiterate the affirmation made in that statement that it has no nuclear weapons on the Korean Peninsula and has no intention to attack North Korea with either nuclear or conventional weapons.
In a parallel process, South Korea should also reiterate its commitment not to receive or deploy nuclear weapons, while reaffirming that there are no such weapons within its borders.
Early steps in that regard would be a declaration by all concerned parties of the existence and location of all facilities either engaged - or that could be engaged - in nuclear weapons-related activities; an agreement to cease all weapons development; and the application of reciprocal arrangements for verification.
In return, in addition to humanitarian and economic support already noted publicly, the United States should agree to a dedicated energy program for North Korea based in part on past efforts related to peaceful production of nuclear energy. This would ensure that reciprocity, balance and proportion are part of the process.
The summit should thus be designed as a launchpad for sustained, structured negotiations leading to the complete, verifiable and irreversible dismantling of the North Korean nuclear-weapons program, while taking concrete steps that reduce tensions and encourage North Korea's continuing compliance.
Such a sustained and smart diplomatic effort is the only viable means to resolving the challenges posed by North Korea. We should all stand ready to promote and support that effort.
Christopher Hill is a former assistant secretary of state for East Asian and Pacific affairs and ambassador to South Korea. Thomas Pickering is a former ambassador to the United Nations, Russia and India.