Saudi King Salman announced on Tuesday the establishment of a center to coordinate humanitarian assistance for Yemen, and invited the United Nations to join in relief work for the Arab country. “We hope that the United Nations will participate effectively with what this center will shoulder, including coordinating all humanitarian and relief works for the Yemeni people with the participation of the countries that are supporting the Gulf initiative,” he said in a speech at the start of a summit of Arab heads of state in Riyadh carried live by the Saudi-owned al-Arabiya channel.