With summit, the two Koreas take step in a new direction, vowing to end the Korean war

PANMUNJOM, SOUTH KOREA - APRIL 27: North Korean leader Kim Jong Un (L) and South Korean President Moon Jae-in (R) applause after announcing the Panmunjom Declaration for Peace, Prosperity and Unification of the Korean Peninsula during the Inter-Korea

North Korean leader Kim Jong Un walked toward South Korean President Moon Jae-in to greet him with a big smile Friday to kick off the inter-Korean summit.

The leaders exchanged greetings as Kim stepped across the military demarcation line in Panmunjom in the Demilitarized Zone to stand side by side with his South Korean counterpart. Kim reached out to hold Moon's hands while they took a step over a cracked slab of concrete into North Korean territory at the world's most heavily armed border. An honor guard and a red carpet ceremony marked the event, the first time a North Korean leader has crossed over to the southern side of the DMZ since the Korean War ended in 1953.

During the closed-door talks between the leaders, the North's nuclear weapons were to top the agenda. Seoul officials said the two leaders had a "sincere and candid" talk on denuclearization, but it's unclear whether the leaders can make any progress on the issue that has bedeviled Korean relations for decades.