1225 GMT January 23, 2021
Hundreds of North Koreans wearing suits and traditional dresses also greeted Moon, carrying flowers and waving Korean peninsula and North Korean flags. A sign behind them read: "We ardently welcome President Moon Jae-in's visit to Pyongyang!"
The two leaders stepped out of the same black Mercedes vehicle with open-top rear seats to arrive at Paekhwawon State Guest House, where Moon will stay, Reuters reported.
The guesthouse was also used by two former South Korean presidents during their own summits with Kim's father, Kim Jong Il, in 2000 and 2007.
The inter-Korean summit, the third between Moon and Kim, will be a litmus test for another meeting Kim has recently proposed to US President Donald Trump.
Trump has asked Moon to be "chief negotiator" between himself and Kim, according to Moon's aides, after Trump cancelled a trip to Pyongyang by his secretary of state last month.
Washington wants to see concrete action toward denuclearization by North Korea before agreeing to a key goal of Pyongyang - declaring an end to the 1950-53 Korean War.
"If North Korea-US dialogue is restarted after this visit, it would have much significance in itself," Moon said before his departure.
Underscoring the challenges ahead, North Korea's official Rodong Sinmun said on Tuesday "the responsibility falls squarely on the United States" for the stalled nuclear discussions.
"It is due to its nonsensical, irrational stubbornness that other issues can only be discussed after our country has completely verifiably, irreversibly dismantled our nuclear capabilities... without showing the intention to build trust including declaring the end of war," the newspaper said in an editorial.
Moon, himself the offspring of a family displaced by the war, has met Kim twice this year at the border village of Panmunjom.
As he landed at Pyongyang's Sunan International Airport on Tuesday morning, Moon was greeted by Kim, his wife Ri Sol Ju and other top North Korean officials, as well as a large honor guard and a military band.
On Wednesday, Moon and Kim plan to hold a second round of official talks after which they are expected to unveil a joint statement, and a separate military pact designed to defuse tensions and prevent armed clashes. Moon will return home early Thursday.
This week's summit comes as the United States presses other countries to strictly observe UN sanctions aimed at choking off funding for Pyongyang's nuclear and ballistic missile programs.
North Korea says it has destroyed its main nuclear and missile engine test site, and has halted atomic and ballistic missile tests but US officials and analysts believe it is continuing to work on its weapons plans covertly.