(CNN)The leaders of the US and South Korea share a common goal: Get North Korea to abandon the nuclear and missile programs that have rapidly expanded under the country’s supreme leader, Kim Jong Un.
But Presidents Moon Jae-in and Donald Trump, who meet for the first time Thursday, have different ideas about how to get there.
Moon, a liberal who took office last month after his conservative predecessor was impeached on corruption charges, is a strong proponent of engagement with Pyongyang.
The Trump administration wants to pressure Kim to the negotiating table but with preconditions.
Moon wants to start talking to Pyongyang to stabilize the situation on the Korean Peninsula sooner than Trump, whose administration won’t negotiate until North Korea agrees to certain terms.
That likely means de-nuclearization must be agreed to up front, experts say.
The stakes are high for both sides, says Adam Mount, a senior fellow at the Center for American Progress.
“(The) alliance is vital for anything the Trump administration wants to do on North Korea, from sanctions enforcement and deterrence to human rights issues, you name it. It’s the most important tool for the US President,” said Mount.
For Moon, the trip — his first abroad — is a chance to personally bring South Korea’s voice to the chorus of those trying to influence US policy on North Korea.
That meant the nascent Trump administration was dealing with a caretaker president, not someone with a clear mandate to make policy decisions.
“South Korea has not really had a seat at the table,” said John Delury, a professor at Yonsei University’s Graduate School of International Relations.
“All this North Korea stuff has been debated and South Korea hasn’t really been part of the conversation as far as Donald Trump is concerned.”
How much damage can North Korea’s weapons do?
Moon believes in the importance of the US-South Korea alliance. But he said during his campaign that South Korea should lead the effort to resolve issues on the Korean Peninsula, rather than the United States, and reiterated that point in an interview with the Washington Post last week.
“Korea should now play a larger and more leading role in this process,” Moon said. “During the periods when South Korea played a more active role, the inter-Korean relationship was more peaceful and there was less tension between the United States and North Korea.”
However, there’s been little easing in tensions since Moon took office: North Korea has conducted three missile tests and Otto Warmbier, an American held in North Korea, died shortly after he was released back to the United States.
Showing the world the US-South Korea alliance is still strong will be key for both sides.
It’s a chance for Trump to marshal an important partner to execute his North Korea plan, especially considering his recent declaration that China — Pyongyang’s most important geopolitical and trading partner — has failed in its efforts so far to rein in its isolated communist neighbor.
“People do want to see how he does abroad, especially in the United States because with South Korean liberals, there’s more tension in the relationship with the United States,” Delury said. “That’s good drama.”
South Koreans will be looking to see how Moon does if things go off script with the off-the-cuff style of Trump.
This could get awkward … or productive
As a presidential adviser, Moon helped craft the Sunshine Policy of the liberal governments of 1998 to 2008, a period of more active engagement and cooperation with North Korea.
Foreign policy of South Korea from 1998 to 2008
Policy of engagement with North Korea on economic and political issues
Two South Korean Presidents traveled to Pyongyang
Earned South Korean President Kim Dae-jung a Nobel Peace Prize
Fewer North Korean nuclear and missile tests during this period
Ultimately failed to stop North Korean nuclear program
Moon campaigned on a promise to bring back engagement and pursue a less hawkish policy than Park, a conservative, though security was not the number one campaign issue for South Koreans, according to opinion polls.
He also maintained that South Korea doesn’t need US permission to speak with the North, something a presidential aide reiterated in an interview with Yonhap News last week.
Presidential spokesman Kwun Hyuk-ki said the “resumption of dialogue with North Korea may need to be pursued in close cooperation and consultation with the United States, but South Korea does not need to be allowed by the US to do so.”
CNN reached out to Moon’s office to confirm the position, but a presidential spokesman said Kwun’s quote was meant to highlight the need to participate in negotiations with the United States, not ignore them altogether.
Though Moon’s insistence that Seoul lead the charge in negotiations with Pyongyang and his ideas about preconditions could be a sticking point with Trump, the president told CBS in an interview through a translator that he believes his North Korea policy is not fundamentally at odds with Trump’s.
“First we must vie for a freeze of North Korea’s nuclear and missile programs, and then as a second phase, try to achieve the complete dismantlement of North Korea’s nuclear program. And I believe there are voices supporting such a step-by-step approach, even in the United States,” Moon said.
Balancing act for new South Korean president
It’s the preconditions for negotiations that drive a wedge between the two parties.
“If the Moon administration is too eager to engage North Korea or the Trump administration is too reticent, then the partnership will sort of fall apart,”Mount said.
Will Pyongyang crash party?
North Korean state-run media slammed the Seoul-Washington alliance in an article published Tuesday, comparing Trump’s “America first” policy to Nazi Germany and likening the US President to Adolf Hitler.
However, it’s unclear if Pyongyang will do anything during the summit. Kim’s regime often times provocations like missile tests for maximum geopolitical impact.
The rogue state conducted a missile test during Trump’s February meeting with Japanese Prime Minister Shinzo Abe and during a summit Chinese President Xi Jinping hosted in May.
The country’s only nuclear test site, Punggye-ri, is believed to be ready for a sixth nuclear test. It’s been that way for months, though no test has come yet.
Conducting such a provocation could backfire, said Mount.
“A test this week will only help strengthen what has been a rough US-South Korea relationship and help the two leaders present a united front,” he said.