President Moon Jae-in and his US counterpart Donald Trump are expected to hold their first summit next month in Washington, as they seek to coordinate North Korea policy following their respective leadership transitions, officials said Tuesday.

A visiting delegation of White House officials in charge of Korea affairs met with a group of foreign affairs and security advisers for Moon, chaired by former Ambassador to Geneva Chung Eui-yong.

The representatives, led by Matt Pottinger, senior director for East Asia at the White House’s National Security Council, and including Allison Hooker, Korea director at the NSC, arrived here late Monday for a two-day stay.

The allies have been striving to arrange an early meeting between the two leaders in a bid to quell concerns about a potential crack in their united front against North Korea, due chiefly to Moon’s pledge to reopen dialogue with the recalcitrant regime.

“The sides have agreed in principle to have a summit late June in Washington and to further consult on a detailed schedule and agenda through diplomatic channels,” Cheong Wa Dae’s senior press secretary Yoon Young-chan told reporters.

“The summit will provide a chance for the two leaders to promote friendship.”

Yoon noted that the envoys also reaffirmed their “common ground” on North Korea, with the ultimate goal of completely abolishing its nuclear and missile programme.

The allies will mobilize all available means including sanctions and dialogue, though dialogue with the North is possible only under the right conditions, and to that aim, they will explore bold and pragmatic steps together.

To facilitate preparations for the summit, Moon plans to dispatch Hong Seok-hyun, former chairman of the JoongAng Ilbo daily and cable network JTBC and who also previously served as ambassador to the US, as his special envoy as early as this week, Yoon said.

On the sidelines of talks with Chung, Pottinger also paid a seven-minute courtesy call to Moon. He then met with Lee Jeong-kyu, Seoul’s deputy foreign minister for political affairs, later in the day.

The delegation’s visit came on the day North Korea launched a new intermediate-range ballistic missile, which is speculated to be capable of flying a distance of at least 4,500 kilometers, and possibly up to 9,000 kilometers.

The latest provocation put Moon’s North Korea policy to an early test. While acknowledging the need for sustained sanctions and pressure, he has conveyed signals of rapprochement with the Kim Jong-un regime, saying during his oath of office that he would visit Pyongyang if conditions are met.

But Pottinger said the allies are “in alignment” that Pyongyang’s behaviour is a threat to regional stability and security, though he fell short of elaborating on the conditions for possible talks with the North.

“Right now we certainly do not see the right conditions in light of the provocations. We would want to see concrete movement to reduce threats — right now the threat is gathering,” he told reporters after the meeting with Lee at the ministry headquarters in Seoul.

On the Terminal High Altitude Area Defence anti-missile system, for which Trump demanded Seoul pay $1 billion (S$1.4 billion), the journalist-turned-policymaker sought to calm concerns, saying it is a “settled matter.”

He also lauded South Korea’s “smooth” leadership transition despite months of political turmoil, saying it made democracy look “so easy.” Moon took office on May 10, one day after a snap election brought by the impeachment of former President Park Geun-hye.

“I have to say how I’m impressed with how smooth the transition is going here — it makes me a little jealous,” Pottinger said.

“We know that it’s often difficult to go through transition especially after a difficult political crisis. I’m just humbled by the example that South Korea had set for the world.”

Detained non-active Jakarta Governor Basuki “Ahok” Tjahaja Purnama is adjusting to life behind bars by reading the Bible and writing, his sister said on Monday.

Fify Lety Indra said that her brother had been an avid reader of the Holy Bible since he was in the university, however his tight schedule while serving as Jakarta Governor sometimes stood in the way.

Now, after being sentenced to two years in prison from his blasphemy case, Ahok continues his religious habit while he also sharpens his Mandarin language.

“My brother also asked for a notebook, I think he needs a medium to share his feelings because sometimes prison cells can be so lonely,” Fifi told The Jakarta Post.

“Who knows, he may produce quality writing in prison, just like Soekarno,” she continued, referring to the country’s first president.

In 2008 Ahok wrote a book titled “Merubah Indonesia” in which he shared his life experiences including his political career and how many of his political opponents quoted the Quranic verse, which later became the centre of his blasphemy case, to campaign against him.

North Korea may be behind the ransomware attacks that disrupted computer systems across the world over the weekend, cyber security experts said Tuesday, suggesting a link between the latest attack and a hacking group associated with Pyongyang.

Researchers from two cybersecurity providers, US software company Symantec and the Russian-based Kaspersky Lab, said that some of the code found in the latest “WannaCry” ransomware was nearly identical to code used by the Lazarus Group, a North Korean-run hacking operation.

An early version of WannaCry is similar to the code used in a 2015 backdoor created by Lazarus Group, which was implicated in a cyberattack on Sony Pictures in 2014 and an US$81 million (S$90 million) heist on a Bangladeshi bank in 2016. The group has allegedly used Bitcoin in their hacking operation.

“This is the best clue we have seen to date as to the origins of WannaCry,” Kaspersky Lab researcher Kurt Baumgartner told Reuters.

Choi Sang-myung, security researcher at Seoul-based software firm Hauri, echoed the view, saying the ransomware attack is attributable to North Korea because they have used their own cryptic hacking logics that have never been found in other malware.

US-based security researchers, however, stuck a more cautious tone, saying the indication is far from conclusive. The researchers said while they did not rule out North Korea as a suspect, it is too early to confirm the link.

Eric Chien, an investigator at Symantec, told The New York Times, that all the findings are “a temporal link.” FireEye researcher John Miller told Reuters that the similarities are “not enough to be strongly suggestive of a common operator.”

The connection was first hinted by Google security researcher Neal Mehta, who posted a cryptic tweet containing only a set of characters. They referred to two portions of code in a pair of malware samples, suggesting potential evidence linking North Korea to the ransomware attack.

The cyberattack, which has crippled around 300,000 computer systems in more than 150 nations since Friday, came amid international condemnation against North Korea’s test-firing of a new type of ballistic missile on Sunday, which Pyongyang said is capable of carrying a nuclear warhead.

Noting that the attack coincided with North Korea’s missile launch, South Korean security experts suggested that the communist regime might have used the attack as an opportunity to demonstrate their capability to defy international pressure against its nuclear ambitions.

“I think there was political motive for North Korea to demonstrate their willingness in time for the establishment of a new government (in South Korea),” said Im Chong-in, professor at Graduate School of Information Security at Seoul-based Korea University. “North Korea is quite likely to use ransomware to secure foreign currency.”

Security Researcher Choi agreed with the idea, saying that North Korea had manufactured ransomware since last August and the cyberattack served as a “perfect opportunity” for the regime to show off their cyber and military capability.

Shoes Tree, a 17-meter-tall art installation made of over 30,000 worn-out shoes, will be revealed outside Seoul Station on Saturday, marking the opening of the city’s first highway-turned-park, Seoullo 7017.

Modeled after New York’s iconic High Line, Seoul’s soon-to-open pedestrian-friendly park stretches for about a kilometer and links seven surrounding areas, including Seoul Station and Namdaemun Market, to 12 pedestrian walkways.

Shoes Tree, a major art piece installed at the centre of Seoullo 7017, was designed and installed by environmental artist Hwang Ji-hae. Flower seeds have been planted inside each shoe.

“We invited Hwang to install Shoes Tree to give a meaning of urban restoration to visitors of Seoullo 7017,” said Choi Kwang-bin, the Seoul Metropolitan Government’s city gardening department.

“Both Shoes Tree and Seoullo 7017 are given new life with new meaning, reborn as a creative upcycling art and a unique park, respectively.”

The reason Hwang used shoes to create a tree was to remember the historical significance of the Yeomcheon-gyo handmade shoes street, located behind Seoullo 7017, the artist was quoted as saying.

The city restoration project of Seoullo 7017 began four years ago to make use of an old overpass that once served as a major road connecting western and central Seoul. Public calls for its removal had mounted after a safety assessment classified the outdated overpass as dangerous in 2006.

The “70” in the name Seoullo 7017 refers to 1970, when the Seoul Station flyover was constructed, while 17 is a reference to the number of walkways connected to it and 2017, when its construction was completed.

Shoes Tree will be exhibited from the official opening of Seoullo 7017, slated for Saturday, until May 29.

Citizens can participate on the opening day by bringing their own shoes, drawing flowers and hanging them on Shoes Tree.

A variety of events involving citizen participation will take place at Seoullo 7017 and continue until June 18, the city said.