US President Joe Biden was expected to announce on Thursday the appointment of a veteran US diplomat as his special envoy for Yemen, a person familiar with the issue said, indicating a more active US role in efforts to end that country’s civil war. Biden was expected to name Timothy Lenderking for the new post in a foreign policy speech, said the source on condition of anonymity. Lenderking’s expected appointment was first reported by the Wall Street Journal. Lenderking has extensive experience dealing with Yemen and the Gulf. He has been the deputy assistant secretary of State for Gulf affairs and served in the US Embassy in Riyadh. Yemen’s civil war pits the internationally recognized government against the Iranian-aligned Houthi militia. The conflict has claimed tens of thousands of lives, including large numbers of civilians, and created the world’s worst humanitarian crisis. An Arab coalition intervened in March 2015 on the side of the government and enjoyed the backing of the former Trump administration, with the war increasingly seen as a proxy conflict between the US and Iran. The United Nations estimates that 80 percent of Yemen’s 24 million people are in need of humanitarian assistance. The UN has been struggling to broker peace talks between the government and the Houthis, an effort that Lenderking likely would be tasked to boost. Biden’s decision to name a special envoy comes as the State Department reviews a Trump administration designation last month of the Houthis as a foreign terrorist organization. The US last week approved all transactions involving Yemen’s Houthi militia for the next month as it carries out the review. But the UN is still hearing concerns that companies are planning to cancel or suspend business with Yemen despite the move. The UN and aid groups have called the designation to be reversed, warning it would push Yemen into a large-scale famine.