Amid high security, North Korean leader Kim Jong Un and his sister Kim Yo Jong flew into Singapore for Tuesday's summit with the United States on separate flights, photos and reports indicated on Sunday.

Kim Jong Un arrived in Singapore's Changi Airport on a VIP-capable Air China 747-400 from Pyongyang at around 3.15pm, with pictures showing his armored Mercedes Benz limousine collecting him directly on the tarmac.