SANAA, Yemen (AP) — The U.N. special envoy for Yemen met Tuesday with the prime minister of the country’s internationally recognized government in the port city of Aden, officials said. He met with Prime Minister Maeen Abdulmalik Saeed in Mashiq Palace, the mission said in a tweet. Grundberg also met with Aydarous al-Zubaidi, the head of the separatists’ Southern Transitional Council, according to the council. The Prime Minister accused the Iranian-backed Houthi rebels of undermining a political settlement with “military escalation and targeting civilians and displaced people,” SABA reported. The U.N. envoy’s efforts come amid an escalation in fighting around the crucial city of Marib, which the Houthi rebels have been trying for months to capture from government forces.