Danish diplomat Ellen Margrethe Løj, the new UN chief for South Sudan, arrived in the conflict-wracked country Tuesday, a week after gunmen shot down a UN helicopter to break the fourth ceasefire deal in nine months.
"It is a huge challenge," Løj told reporters of the task ahead after arriving in the capital Juba, although she said she was "looking forward" to the task.
Løj, 65, the new UN special representative and head of the UN peacekeeping mission in South Sudan (UNMISS), arrives after almost nine months of conflict and amid warnings there could be a famine in the world's youngest nation if the fighting continues.
The helicopter was shot down last week by unknown attackers, killing three Russian crew members and injuring another, and breaking a ceasefire only one day old.
Løj's predecessor, Norway's Hilde Johnson, said when she left the country in July that South Sudan's "self-serving elite" of leaders and rebels were sick with "the cancer of corruption."
She said they were responsible for a looming "man-made famine".
Thousands of people have been killed and more than 1.8 million have fled a civil war in the country, sparked by a power struggle between President Salva Kiir and his sacked deputy Riek Machar.
Løj, a former ambassador to the Czech Republic, the United Nations and Israel, also served as special envoy to Liberia from 2008 to 2012.