US ambassador arrives in DR Congo

She arrived aboard a military plane accompanied by more than 30 people, an airport source said.

"Indeed, she has arrived," Foreign Minister Leonard She Okitundu confirmed to AFP.

Haley will stay in the DRC until Friday, the last leg of her African trip which has taken her to Ethiopia and South Sudan.

Violence has intensified in recent months in South Sudan and the DRC, despite a strong peacekeeping presence.

With 18,000 blue helmets, the UN peacekeeping mission in the DRC is the largest in the world.

Haley Wednesday voiced "disappointment" and her worries about the situation in South Sudan, which is devastated by a civil war, after meeting in Juba with South Sudanese President Salva Kiir.

The United States has invested $11 billion (nine billion euros) in the country under Kiir's leadership.

Haley was escorted out of a UN camp she was visiting in South Sudan Wednesday when protestors angry at Kiir turned up.

It is the first trip to Africa for Haley, who is the most senior Trump administration official to visit the continent.

According to official and diplomatic sources in Kinshasa, she will travel to North Kivu on Thursday before returning to Kinshasa for meetings with President Joseph Kabila and also the opposition and civil society.

Haley is expected to press Kabila to agree to a timetable for elections.

Her visit comes as the vast, mineral-rich central African country is facing a humanitarian, security and political crisis.

Polls were due this year under a transitional deal with the opposition aimed at avoiding fresh political bloodshed after Kabila refused to step down when his second mandate ended in December.

The international community has pressed for a vote to choose a new head of state to be held as soon as possible but no timetable has been set so far.

The electoral commission responsible for organising the ballot says it will be impossible before early 2019.

Under the deal, Kabila is allowed to remain in office pending the elections, ruling in tandem with a transitional watchdog and a new premier, to be chosen within opposition ranks.

One of the main obstacles to organising elections is the continuing violence in the central, diamond-rich Kasai region, where a rebellion has been going on for a year now, the commission chief has said.