Indonesia's President Joko Widodo and Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan react after they plant a tree during a welcoming ceremony at the presidential palace in Bogor, Indonesia, July 24, 2019.

Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan and Indonesian President Joko Widodo walk during a welcoming ceremony at the presidential palace in Bogor, Indonesia, July 24, 2019. Dita Alangkara/Pool via Reuters.

Indonesia's President Joko Widodo and Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan hold a pitcher as they plant a tree during a welcoming ceremony at the presidential palace in Bogor, Indonesia, July 24, 2019.

Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan and Indonesian President Joko Widodo walk as they inspect honor guards during their meeting at the presidential palace in Bogor, Indonesia, July 24, 2019. Dita Alangkara/Pool via Reuters.

Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan and Indonesian President Joko Widodo wave to photographers during their meeting at the presidential palace in Bogor, Indonesia, July 24, 2019. Dita Alangkara/Pool via Reuters.

Indonesia's President Joko Widodo and Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan talk as they prepare to plant a tree during a welcoming ceremony at the presidential palace in Bogor, Indonesia, July 24, 2019.

Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan and Indonesian President Joko Widodo walk as they inspect honor guards during their meeting at the presidential palace in Bogor, Indonesia, July 24, 2019. Dita Alangkara/Pool via Reuters.

Indonesia's President Joko Widodo pours waters as Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan stands, as they plant a tree, during a welcoming ceremony at the presidential palace in Bogor, Indonesia, July 24, 2019.

Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan and Indonesian President Joko Widodo walk down the steps of the presidential palace during their meeting in Bogor, Indonesia, July 24, 2019. Dita Alangkara/Pool via Reuters.

Indonesia's Minister of Tourism Arief Yahya and Minister of Economy of the United Arab Emirates Sultan bin Saeed Al Mansoori hold documents during Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan visit at the presidential palace in Bogor, Indonesia, July 24, 2019.

Indonesian President Joko Widodo gestures as he talks with Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan during their meeting at the presidential palace in Bogor, Indonesia, July 24, 2019. Mast Irham/Pool via Reuters.

Indonesia's Minister of Tourism Arief Yahya shakes hands with the Minister of Economy of the United Arab Emirates Sultan bin Saeed Al Mansoori, during Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan visit at the presidential palace in Bogor, Indonesia, July 24, 2019.

Indonesia's president Joko Widodo and Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan walk as they prepare to plant a tree during a welcoming ceremony at the presidential palace in Bogor, Indonesia, July 24, 2019., 2019.

Indonesia's president Joko Widodo talks to Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan during a meeting at the presidential palace in Bogor, Indonesia, July 24, 2019.

Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan and Indonesian President Joko Widodo are greeted by students during a meeting at the presidential palace in Bogor, Indonesia, July 24, 2019. Mast Irham/Pool via Reuters.

Indonesian President Joko Widodo talks with Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan during their meeting at the presidential palace in Bogor, Indonesia, July 24, 2019. Mast Irham/Pool via Reuters.

Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan places soil, next to Indonesia's President Joko Widodo, as they plant a tree during a welcoming ceremony at the presidential palace in Bogor, Indonesia, July 24, 2019.

Indonesia's President Joko Widodo talks to Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan during a meeting at the presidential palace in Bogor, Indonesia, July 24, 2019.

Indonesia's president Joko Widodo talks with Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan as they prepare to plant a tree during a welcoming ceremony at the presidential palace in Bogor, Indonesia, July 24, 2019., 2019.

Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed Al Nahyan and Indonesian President Joko Widodo walk as they inspect honor guards during their meeting at the presidential palace in Bogor, Indonesia, July 24, 2019. Mast Irham/Pool via Reuters.