UN Secretary General Antonio Guterres says the UN pledging conference on Yemen in Geneva has been a "success" as "donors have pledged 30% more than last year to help address the dramatic humanitarian situation". 2.6 billion US dollars have been pledged but the UN has said that $4.2 billion is needed to provide relief to more than 21 million people across the war-torn country, where 80 percent of the population is estimated to need assistance.