Washington - The US to bounce additional humanitarian assistance to Yemen in Geneva this week. US Agency for International Development (USAID) Counselor Thomas H. Staal is heading the US delegation to Switzerland to attend the High Level Pledging Event for the Humanitarian Response in Yemen, due on 24-26 April and will meet with "partners and government officials to discuss mobilizing urgently needed resources for the Yemeni people," a statement by USAID said on Monday. The US has pledged just under USD 404 million to respond to urgent needs in Yemen since 2015. According to the United Nations Office for the Coordination of Humanitarian Affairs (OCHA), 18.8 million Yemenis are in need of humanitarian or protection assistance, among them, 10.3 million "require immediate assistance to save or sustain their lives," making Yemen "the largest humanitarian crisis in the world.