The two Koreas marched together and South Korea's president shared a historic handshake with Kim Jong Un's sister as the Pyeongchang Winter Olympics opened in a spirit of intense rapprochement on Friday.

At a glittering but sub-zero ceremony, South and North Korea brought the crowd to its feet as they entered behind the blue-and-white Korean unification flag.

South Korean President Moon Jae-in shook the hand of a smiling Kim Yo Jong, the powerful sister of North Korean leader Kim Jong Un, as he entered the VIP seating section, and again as the Korean athletes marched.

It cemented what has been a rapid improvement in Korean ties since North Korea — after months of fierce nuclear rhetoric and missile tests — agreed last month to attend its first Olympics in the South.