Korea had demanded that Secretary of State Mike Pompeo be excluded from future nuclear talks.
The test comes during an apparent deadlock in nuclear disarmament talks after the failed summit in Hanoi between Kim and President Donald Trump earlier this year.
Kim blamed the collapse of his summit with Trump in February on what he described as unilateral demands by the United States, which he said raised questions over whether Washington has genuine willing
Both Trump and Moon are heavily invested in bringing North Korea out of the cold. But the unsuccessful summit in Vietnam was a setback for the two allies that has yet to be resolved.
Moon, for his part, has called for an easing of sanctions, including those holding back joint economic projects between North and South Korea.
The Hanoi summit fell apart as Kim and Trump failed to find common ground over how to match Pyongyang's denuclearization steps with Washington's sanctions relief.
After the opening ceremony, the first 120 tourists crossed the border. Chinese tourism to the North has picked up as relations between the countries have improved in recent years.
Trump and Kim held their first landmark summit in Singapore last June, where the North Korean leader signed a vaguely-worded deal on the "denuclearisation of the Korean peninsula.
South Korean President Moon Jae-in, who facilitated US-North Korean talks last year, is to travel to Washington next week to discuss nuclear diplomacy with Trump.
Seoul's foreign ministry said a South Korean ship and three others had been detained in the country, suspected of undermining the economic measures against the North.
The Security Council's panel of experts that monitors the sanctions on North Korea said the cyberattack in August last year was carried out "by an advanced persistent threat group" from that country.
Donald Trump orders withdrawal of sanctions against North Korea immediately after Treasury imposes them
President Trump's unusual move comes after his second summit with Kim, held last month in Hanoi, Vietnam.
Trump told a post-summit press conference in Hanoi that the North Korean leader had promised he would maintain his moratorium on missile and nuclear tests.
The satellite imageries were released days after the second US-North Korea summit in Vietnam ended without any agreement.
This year's turnout fell just short of 100 percent as those "abroad or working in oceans" were unable to take part, the North's official KCNA news agency reported.