In the al-Jafeenah camp for internally displaced people outside the Yemeni city of Marib, Jamal al-Jaberi, forced to flee fighting near his home, is counting on the United States to help broker a peace deal and end the seven-year war. The Yemen conflict has triggered the world"s worst humanitarian crisis, and U.S. President Joe Biden has made ending it one of his top foreign policy priorities. But the latest round of talks failed to persuade opposing forces - backed by regional rivals Saudi Arabia and Iran - to back down, according to three sources familiar with the negotiations, including a U.S. official. Still, those caught up in fierce battles around Marib in central Yemen, where the worst of the fighting has been concentrated for months, have not lost hope. "We hope the United States and the (United Nations) Security Council will strive to end the war and the attack on Marib, because in Marib there are a lot of refugees from every part of the country," said Jaberi. The Marib region is the last stronghold of the Saudi-backed government, which has been at war against Iran-aligned Houthi forces since 2014. Fighting over Marib and its vast gas fields has killed thousands of fighters from both sides and threatened years of peace efforts, including a fresh push from the United States. U.S. officials, including Yemen envoy Tim Lenderking, have held several meetings with Saudi officials, Yemeni ministers and Omani mediators over the last two weeks. U.N. Special Envoy Martin Griffiths has also joined the U.S. shuttle diplomacy. More than 100,000 people have been killed in the war, most of them civilians. Millions of Yemenis rely on humanitarian assistance to survive, and a second wave of COVID-19 has strained what remains of the health system. The United States has pressed the Saudi-led coalition to lift the blockade of Houthi-controlled Sanaa airport and Hodeidah port to encourage the Houthis to stop missile and drone attacks on Saudi Arabia and the assault on Marib. "The United States believes that the opening of ports and the airport is a fundamental pillar of our approach towards Yemen," said the U.S. official. "IMMENSE SUFFERING" Hodeidah is the main entry point for Yemen"s commercial and aid imports, while Sanaa airport is the only airfield under the control of the Houthis. Saudi Arabia and Yemen"s government have insisted that lifting the blockade should be tied to other elements of a wider deal - something the Houthis reject. "The humanitarian situation should not be subject to bargain ... If they lift the blockade we are all in for ceasefire talks," Houthi chief negotiator Mohammed Abdulsalam told Reuters. A Saudi source who declined to be named said Hodeidah port was fully open to all commodities under U.N. supervision and that the airport was open for U.N. and humanitarian flights. He added that a ceasefire would ease the humanitarian crisis and that the Yemeni government was prepared to negotiate with the Houthis. U.N. envoy Griffiths said that despite international efforts, "we are not where we would like to be in reaching a deal. "Meanwhile, the war continued unabated causing immense suffering to the civilian population," he said in a statement last week. In Marib city, families worry they will not be able to afford traditional gifts for their children as they, along with fellow Muslims around the world, prepare to celebrate the Eid-al-Fitr religious holiday. Markets were teeming with people trying to buy new clothes and dried fruits ahead of the festivities. "Prices are too high for us to buy clothes for our kids, but at least, thank God, we made it out of our village," said Shaher Nasser al-Koule, now living in the sprawling tent camp of Jafeenah, 5 km (3 miles) south of Marib. There, children gathered barefoot to play in a dusty square strewn with rocks, trash, dilapidated trucks and debris from rockets and mortar shells.