North Korean leader Kim Jong Un will arrive in Singapore on Sunday for his historic meeting with U.S. President Donald Trump in the city-state, a Singapore diplomatic source said Saturday.

Trump and Kim are scheduled to hold talks in Singapore on Tuesday in the first-ever summit between sitting leaders of the United States and North Korea, with the focus on whether Washington and Pyongyang will alleviate security tensions and eliminate the threat of war.

Kim will be making only his second overseas trip by plane since taking power in 2011.

When Kim visited Beijing in March in his first foreign trip as leader, he went by a special train, following the tradition set by his father and grandfather, former leaders Kim Jong Il and Kim Il Sung.

Early last month, however, Kim visited the northeastern Chinese city of Dalian using his private jet, which he previously used only for travel within North Korea. That sparked speculation that he would use the same aircraft to visit Singapore.

Some media have reported that Kim may head to Singapore using a different airplane offered by China.

Trump, meanwhile, is also expected to arrive in Singapore on Sunday. The White House has said he would leave the Group of Seven summit in Canada earlier than initially planned, skipping the last session on climate change and oceans on Saturday to head to Singapore.