The summit between US President Donald Trump and North Korean leader Kim Jong-un in Singapore is an important breakthrough in the history of North Korea-US relations. It brings the nuclear issue closer to resolution. Although more likely to be a consensus, the goal of complete denuclearization of the Korean Peninsula was reaffirmed in the joint statement that the two countries signed. The Trump administration also pledged to halt the annual US-South Korea joint military drill, which fulfills the achievement of the summit.

Trump showed his high spirits during the press conference after the meeting and again appreciated North Korea's change for the better on Twitter. It shows the two countries have broken more common ground than the current statement shows. It cannot be ruled out that Kim and Trump may visit each other this year.

The Korean Peninsula is the last remnant of the Cold War and the state of armistice has lasted for 65 years. During the Singapore summit, the two countries agreed to establish a robust peace regime on the peninsula, which is a praiseworthy breakthrough.

But one shouldn't be overoptimistic about improvement in North Korea-US relations in the future. They still diverge significantly on the specific way of realizing complete denuclearization on the peninsula. Although the complete, verifiable and irreversible denuclearization (CVID) was not mentioned in the joint statement, it doesn't mean that the US has given it up. The two countries will focus on the meaning, timeline and route of denuclearization in further negotiations.

Averse to CVID, Pyongyang believes that accepting it will look like a vanquished loser. North Korea hopes for a complete, verifiable and irreversible guarantee and will never surrender when it can't ensure its own safety, especially political security. 

The US is still tough on sanctions. It insists that lifting sanctions will only come after complete denuclearization. US National Security Advisor John Bolton had previously suggested that Libya could serve as a model for persuading North Korea to denuclearize, which irritated Pyongyang. The Trump administration holds that "maximum pressure" is the main reason that brings North Korea to the negotiation table.

As Pyongyang has promised to work toward complete denuclearization and demolished its nuclear test site, it hopes that Washington will ease sanctions. If the US remains indifferent, North Korea may adopt a tough stance again out of frustration and go back on what has been a thaw in ties. Russia has urged the UN Security Council to partly lift sanctions on North Korea to encourage Pyongyang to come around.

North Korea and the US still lack mutual trust - a problem the summit couldn't resolve. There were times when the two countries reached a consensus but soon stepped back from it, and the capricious Trump once decided to cancel the summit. With domestic pressure building up, Trump and US Secretary of State Mike Pompeo may go back on what they promised.

Meanwhile, there are still voices in Washington that proposed to tighten the screws on Pyongyang. For example, Bolton hasn't given up the idea of using military attacks and Vice President Mike Pence is skeptical about getting in touch with North Korea. Nancy Pelosi, the Minority Leader of the US House of Representatives, strongly criticized the Kim-Trump summit and regarded the US as the loser. With the upcoming midterm elections Trump may go backwards on his policies. 

Also third-party countries such as South Korea and Japan may pin down North Korea-US ties. During the press conference, Trump pledged to stop "war games" with South Korea to save money. This unilateral announcement has worried Seoul while Japan is disappointed that the US didn't factor in North Korea's medium- and short-range ballistic missiles. Besides, the issue of abducted Japanese citizens, which Tokyo is concerned about, seems not to have been brought up at the summit. Tokyo and Seoul are worried that US troops may be eventually pulled out of the peninsula.

The Kim-Trump summit is a historic moment, but it hasn't come to a historic turning point in North Korea-US relations. The priority now is to maintain the momentum of dialogue, especially making sure that the US doesn't back out. North Korea should also maintain its peace offensive with actions like truthfully reporting its nuclear weapons and facilities. Besides, Pyongyang and Seoul should put the Panmunjom Declaration into effect. All parties concerned should be patient, prudent and willing to make compromises.