North Korea has started to dismantle key missile test sites, revealed a Washington-based think tank on Monday. The July 20 images showed work at the Sohae Satellite Launching Station to dismantle a building used to assemble space-launch vehicles and a nearby rocket engine test stand used to develop liquid-fuel engines for ballistic missiles and space-launch vehicles, the 38 North think tank said. The development is seen as a first step toward fulfilling a pledge made to US President Donald Trump on the denuclearization of the Korean peninsula. “Since these facilities are believed to have played an important role in the development of technologies for the North’s intercontinental ballistic missile program, these efforts represent a significant confidence-building measure on the part of North Korea,” it said in a report. Trump said after his unprecedented June 12 summit with North Korean leader Kim Jong Un in Singapore Kim had promised that a major missile engine testing site would be destroyed very soon. Trump did not identify the site, but a US official subsequently told Reuters that it was Sohae. An official said on Tuesday South Korea’s presidential Blue House was briefed about the site’s dismantlement based on government intelligence but did not elaborate. According to Yonhap, Nam Gwan-pyo, deputy director of the South’s national security office, said: “It’s better than doing nothing. And it seems like they are going step by step toward denuclearization.” The 38 North report comes amid growing questions about North Korea’s willingness to live up to the commitments Kim made at the June summit, particularly to work toward denuclearization. US officials have repeatedly said North Korea has committed to giving up a nuclear weapons program that now threatens the United States, but Pyongyang has offered no details as to how it might go about this. Shares of South Korean companies with exposure to North Korea rose after the news that the satellite site was being dismantled. The development has not stemmed suspicions that Pyongyang was circumventing UN sanctions. Gasoline prices in North Korea have nearly halved since late March, market data analyzed by Reuters shows, adding weight to suspicions that fuel is finding its way into the isolated economy from China and elsewhere despite the sanctions. The UN Security Council passed a resolution in December to ban nearly 90 percent of refined petroleum exports to North Korea over its nuclear and missile programs. Gasoline was sold by private dealers in the capital Pyongyang at about $1.24 per kg as of Tuesday, down 33 percent from $1.86 per kg on June 5 and 44 percent from this year’s peak of $2.22 per kg on March 27, according to Reuters analysis of data compiled by the Daily NK website. Diesel prices are at $0.85 per kg, down about 17 percent from March. The website is run by North Korean defectors who collect prices via phone calls with traders in the North. “My assessment is that there was a greater inflow (of fuel supplies) from abroad, especially China since Kim’s trips there,” said Kang Mi-jin, who works at Daily NK and speaks regularly to sources inside North Korea. Senior US officials called on Kim on Friday to act on his promise to give up his nuclear weapons and said the world, including China and Russia, must continue to enforce sanctions on Pyongyang until he does so. The US State Department issued an advisory on Monday together with the departments of Treasury and Homeland Security alerting businesses to North Korea’s sanctions-evasion tactics. It said they should “implement effective due diligence policies, procedures, and internal controls to ensure compliance with applicable legal requirements across their entire supply chains.” Separately on Tuesday, South Korea’s Defense Ministry said it was planning “a test reduction of some guard post troops and equipment” along the heavily fortified Demilitarized Zone (DMZ) that divides North and South Korea.