UN Secretary-General Antonio Guterres has begun searching for a new envoy to Libya to replace Lebanon’s Ghassan Salame, diplomatic sources said Wednesday, after the United States refused to endorse the previous candidate. Former Algerian foreign minister Ramtane Lamamra seemed to be all but confirmed in early March. But the US increasingly posed "questions" about his candidacy, even though "everyone else" supported him, a diplomat said, according to AFP. Wednesday, during a closed-door meeting on Libya, a UN official told the Security Council that Guterres had launched a search for a new candidate, another source said. Guterres "is working hard to make a proposal," the source said on condition of anonymity. The US mission to the UN gave no further explanation for opposing Lamamra, 67, who served as Algerias foreign minister from 2013 to 2017 and as African Union commissioner for peace and security from 2008 to 2013. He is considered an experienced diplomat and has been a mediator in several African conflicts, notably in Liberia. A source suggested that Washington could have considered Lamamra as too close to Russia, which is accused of sending “mercenaries” to support the Libyan National Army, an accusation that Moscow denies. Salame quit in early March following the repeated failure of efforts to restore order, although he said his resignation was for health reasons. He had served in the role since June 2017.