President Moon Jae-in invited Pope Francis to North Korea again as he made another effort to reopen nuclear talks, at a meeting at the Vatican on Friday.

The meeting was the first official stop on his trip to attend a Group of 20 summit over the weekend and a UN climate meeting that ends Tuesday.

“Your visit to North Korea would be the new momentum for peace on the Korean Peninsula. South Koreans are looking forward to it,” Moon said, repeating an invitation from North Korean leader Kim Jong-un that he relayed verbally in 2018 when he met the pope for the first time.

The pope responded the same way he did back then, saying he would gladly make the trip if North Korea formally invites him. No papal trip took place, as Kim never sent a formal invitation.

Pyongyang is now demanding concessions from Seoul and Washington to restart talks, such as rolling out sanctions relief and suspending their annual military drills. The two allies have yet to coordinate their response. 

Meanwhile, the Moon government has proposed signing a declaration to end the 1950-53 Korean War. Seoul believes it will rebuild enough trust to resume talks, but Washington is wary of the proposal, with its national security adviser indicating it had a different perspective on the issue.

Experts said it was not just the political landscape blocking the pope’s visit, noting that the coronavirus pandemic poses a serious challenge to both the Vatican and North Korea.

“North Koreans would have to be vaccinated. They need vaccines or antiviral pills at least, before any pontiff sets foot there. And the pope would have to self-quarantine, but is that all really something we can imagine?” said Cheong Seong-chang, director of the Center for North Korean Studies at the Sejong Institute.

Cheong said Moon would not see the trip take place under his term, because North Korea needs more time to prepare for such a landmark meeting. Pyongyang, which has closed its borders, claims to have had no infections but is struggling with vaccinations and economic disruptions caused by the pandemic.

After meeting with the pope, Moon will take part in the two-day G20 summit in Rome on Saturday, where countries are divided over phasing out coal and limiting global warming to 1.5 degrees Celsius. The first face-to-face meeting of the group in two years will deal with managing an economic recovery from the COVID-19 crisis.

On Monday, Moon will fly to Glasgow, Scotland, for the two-day UN climate summit known as COP26, which involves almost 200 countries, including the G20 nations that account for more than an estimated 80 percent of global greenhouse gas emissions.

There, Moon is expected to introduce his plan to cut South Korea’s emissions 40 percent by 2030 compared to 2018 levels. Moon said the country would go carbon-free by 2050, but experts have cast doubt over how realistic the proposal is.

On the sidelines of the gatherings, Moon could meet with US President Joe Biden to discuss North Korea, a Seoul official said. Cheong Wa Dae has not publicly confirmed reports that the two leaders could meet to work out differences over their approach to North Korea.

Moon will return home Friday after meeting the Hungarian president during a state visit, the first in two decades. He will also pay respects to 25 South Koreans who were killed in a Budapest boat accident in 2019.