<p>The United States, a key supporter of South Sudan, said it was calling back its ambassador for consultations as it shows frustration with duelling leaders' failure to form a government.</p>.<p>Secretary of State Mike Pompeo wrote on Twitter that he called back the ambassador "as we re-evaluate our relationship with the government of South Sudan."</p>.<p>"We will work with the region to support efforts to achieve peace and a successful political transition in South Sudan," he said.</p>.<p>The United States, which contributes about USD 1 billion a year in mostly humanitarian aid for the young country, has been especially vocal in its exasperation over the lack of progress in South Sudan.</p>.<p>South Sudan President Salva Kiir and rebel chief Riek Machar fell out in 2013 -- two years after the largely Christian nation won independence from Sudan with strong US support -- sparking a conflict that has left hundreds of thousands dead.</p>.<p>The two leaders missed a November 12 deadline to form a unity government. African mediators gave them another 100 days, the second extension.</p>.<p>The US ambassador in Juba, Thomas Hushek, will hold talks in Washington on the re-evaluation of the relationship, State Department spokeswoman Morgan Ortagus said.</p>.<p>Tibor Nagy, the assistant secretary of state for African affairs, said earlier this month that he believed Kiir and Machar had grown content with the status quo.</p>.<p>"The international community is providing the food, the medicines, basically all of the human needs that are the responsibilities of governments to do. They're basically sitting back," he said.</p>
<p>The United States, a key supporter of South Sudan, said it was calling back its ambassador for consultations as it shows frustration with duelling leaders' failure to form a government.</p>.<p>Secretary of State Mike Pompeo wrote on Twitter that he called back the ambassador "as we re-evaluate our relationship with the government of South Sudan."</p>.<p>"We will work with the region to support efforts to achieve peace and a successful political transition in South Sudan," he said.</p>.<p>The United States, which contributes about USD 1 billion a year in mostly humanitarian aid for the young country, has been especially vocal in its exasperation over the lack of progress in South Sudan.</p>.<p>South Sudan President Salva Kiir and rebel chief Riek Machar fell out in 2013 -- two years after the largely Christian nation won independence from Sudan with strong US support -- sparking a conflict that has left hundreds of thousands dead.</p>.<p>The two leaders missed a November 12 deadline to form a unity government. African mediators gave them another 100 days, the second extension.</p>.<p>The US ambassador in Juba, Thomas Hushek, will hold talks in Washington on the re-evaluation of the relationship, State Department spokeswoman Morgan Ortagus said.</p>.<p>Tibor Nagy, the assistant secretary of state for African affairs, said earlier this month that he believed Kiir and Machar had grown content with the status quo.</p>.<p>"The international community is providing the food, the medicines, basically all of the human needs that are the responsibilities of governments to do. They're basically sitting back," he said.</p>