The United Nations Security Council will vote Friday to cut the number of troops in its peacekeeping mission in the Democratic Republic of Congo.
US ambassador Nikki Haley said the force's currently authorized strength of 19,815 would be cut by 3,600 -- but that 3,100 of these places are already unfilled.
The central African giant is under pressure to hold key elections this year, despite ongoing fighting between armed factions, political chaos and widespread corruption.
But UN member states, in particular President Donald Trump's new US administration, want to scale back UN spending on its missions around the globe.
According to a draft council resolution seen by AFP, which diplomats are expected to pass unanimously, the Blue Helmet military force will be reduced to 16,215.
In practice, this will mean 500 fewer troops on the ground, since the mission, known as MONUSCO, was already not at full strength. UN police numbers are unchanged.
"You have to look at the political side of the peacekeeping mission," Haley said.
"We're trying to get aid to the people on the ground, and the government is not letting us. Adding more troops will not change that problem."
"All we're doing is reducing 500 troops," she said, promising the whole strategy of the mission would be reviewed and the Congolese government held accountable.
- 'Good agreement' -
France had warned against too dramatic a cut in the size of the forces, warning that it might endanger what little progress has been made towards stabilizing the DRC.
But France's UN ambassador pronounced himself satisfied with the draft resolution.
"You know it is the outcome of an important negotiation. And so if things go well we will go for a vote tomorrow at noon," Francois Delattre told reporters.
"And I think it is important for DRC, for MONUSCO and for peacekeeping in general. This is a good agreement."
On Wednesday, Haley said she would use her presidency of the Security Council next month to launch a review of peacekeeping.
"We will go back to first principles and ask hard questions," she told the Council of Foreign Relations, a New York think tank.
"What was the original intent of the mission? Is the mission achieving its objective? Do we have an exit plan and is there accountability?"
- General strike -
Meanwhile, the situation on the ground in the DRC is tense.
On the last day of 2016, President Joseph Kabila signed a deal to share power with the opposition as officials work to set up national elections later this year.
The agreement was never fully implemented, despite international pressure, and an opposition umbrella group has called for a general strike from Monday in protest.
Kabila first took power in 2001 to replace his assassinated father as war ravaged the country.
His unwillingness to step down and enable elections at the end of his constitutional mandate last year led to protests in which at least 17 people were killed.
Under a deal brokered by the country's influential Roman Catholic bishops, Kabila was allowed to stay in office in tandem with a transitional body and a new premier.
But talks on implementing the accord appear to have broken down, and violence has flared.
Last week, 39 police were killed in an ambush by rebels in the remote central region of Kasai.
In a separate incident, two foreign UN experts, an American and a Swede, were killed in the same region.
Diplomats at the UN told AFP that the murdered pair had been investigating reports of mass graves.
On Tuesday, the UN, the European Union and the African Union called for an opposition figure to be named premier as had been agreed under the December 31 deal.
"A step forward of this kind will help the country's stabilization process, the restoration of public order... and the holding of elections as scheduled," they said.
The opposition coalition was formed around Etienne Tshisekedi, a veteran foe of successive Kinshasa regimes who died in Brussels in February, aged 84.