The United Nations Security Council will vote Friday to cut the number of troops and police in its peacekeeping mission in the Democratic Republic of Congo by around seven percent.

The lawless central African giant is under pressure to hold key elections this year, despite 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 expected to pass unanimously, the force of 19,815 uniformed personnel will be reduced to 18,316.

The military part of the UN Mission, known as MONUSCO, was authorized to deploy 18,232 Blue Helmets.

This will be reduced under the draft plan to 16,215, but diplomats said that the actual force currently on the ground was already down to around 17,000.

"The most important thing is that this figure was decided after a study of the situation on the ground, the mandate of the mission and its needs," one diplomat said.

"It wasn't cut just any old how, it preserves the mission's ability to operate."

The smaller force will be equipped to be more mobile and to cover more ground in a sprawling country with dense forests and poor roads controlled by a patchwork of factions.