North Korean leader Kim Jong-un and United States President Donald Trump reached Singapore on Sunday for a historic summit scheduled for Tuesday. The two leaders will meet on Tuesday morning on the resort island of Sentosa.

Singapore Foreign Affairs Minister Vivian Balakrishnan welcomed Kim at Changi Airport after his longest trip overseas as head of state. Trump arrived in Singapore later on Sunday Paya Lebar Air Base.

Trump will meet Singapore’s Prime Minister Lee Hsien Loong on Monday. His meeting with Kim will start at 9 am on Tuesday.

This is the first time that a North Korean leader is holding a meeting with a sitting US president. Since the Korean War in the 1950s, the leaders of the two countries have never met or even spoken on the phone, Reuters reported. Trump and Kim will discuss the denuclearisation of North Korea and the formal ending of the Korean War.

Singapore has restricted its airspace temporarily for parts of June 11, 12 and 13. All aircraft arriving into Singapore Changi Airport will be required to reduce speed and face some restrictions on runway use “for reasons of national security”, a government notice said.

Trump has said that the formal ending of the Korean War is on the agenda. The 1950 to 1953 conflict had only ended with a truce but no final peace treaty was signed.

The summit comes months after the tensions between the US and North Korea escalated after Pyongyang stepped up efforts to boost its nuclear weapons programme. The two leaders began to frequently trade ridicule, insults and threats against each other, and the United Nations strengthened sanctions against North Korea. In March, however, Trump accepted an invitation from Kim to meet him.