A deputy leader of Libya's Government of National Accord (GNA) announced his resignation on Monday, saying the U.N.-backed administration had failed to tackle urgent problems arising from years of conflict and political disarray. The resignation of Musa al-Koni casts doubt on the future of the government in its current form, just over a year after it was launched under a U.N.-mediated deal that had only partial support from Libya's rival factions, Reuters reported. Western powers backed the GNA to tackle Islamic State, boost Libya's oil production, and help stem the flow of sub-Saharan migrants from Libya to Europe. But though Islamic State has been ousted from its former stronghold of Sirte and oil production has recovered slightly, the GNA has largely failed to exert its authority over a country that slid into lawlessness after the 2011 uprising that toppled Muammar Gaddafi. The GNA's leaders, including Koni, arrived in Tripoli in March, but have struggled to impose their authority. Militias still hold real power and living conditions have deteriorated. "I announce my resignation due the failure of the Presidential Council, because it holds responsibility for the killing, kidnapping, and rape that happened over the past year," Koni told a press conference in Tripoli on Monday.