North Korean leader Kim Jong Un is expected to fly into Singapore's Changi Airport on Sunday ahead of a high-stakes summit with U.S. President Donald Trump, a source involved in the planning of the trip said Friday.

Pictures of U.S. military aircraft at nearby Paya Lebar air base, including a white-topped helicopter commonly used for transporting high-ranking U.S. officials, were published in a newspaper Friday.

Talks between the leaders on June 12 are expected to center on ending the North's nuclear weapons and missiles programs in return for diplomatic and economic incentives.