By Michelle Nichols
UNITED NATIONS (Reuters) - The U.N. Security Council has agreed a compromise on a reduced troop cap of 16,215 for its peacekeeping mission in Democratic Republic of Congo, the United Nations' largest and most expensive, after the United States asked for it to be cut by a quarter, diplomats said on Thursday.
The 15-member body is due to vote on Friday to renew the mandate for the $1.2 billion operation, known as MONUSCO, amid U.N. warnings that violence is spreading across the central African state ahead of planned elections before the end of 2017.
"We have an agreement," French U.N. Ambassador Francois Delattre told reporters on Thursday.
The United States had wanted the troop cap to be cut to 15,000, diplomats said. Despite a request by Secretary-General Antonio Guterres to add two extra police units - 320 officers - the council has agreed to a Washington demand to keep the current total of 1,050 officers, according to the draft resolution.
Instead the draft text asks Guterres to "explore the possibility of inter-mission cooperation through appropriate transfers of troops and their assets from other United Nations missions to MONUSCO" if needed and subject to council approval.
France leads Security Council action on Congo and had proposed a troop cap of 17,000, diplomats said. The mission currently has a cap of 19,815, though there are only 16,893 soldiers on the ground after the previous U.N. chief Ban Ki-moon made cuts in 2015 and 2016.
It is the first peacekeeping mission to come up for renewal since U.S. President Donald Trump proposed that Washington - the largest U.N. contributor - cut funding. U.S. Ambassador Nikki Haley is reviewing the 16 U.N. peacekeeping operations.
Haley said on Wednesday that U.N. peacekeepers in the Democratic Republic of Congo are aiding a government that is "corrupt and preys on its citizens." [L2N1H60KU]
Resource-rich Congo, which gained independence from colonial power Belgium in 1960, has never had a peaceful transition of power and President Joseph Kabila's refusal to stand down when his final term expired in December has raised fears the chronically unstable country could slide back into civil war.
Opposition leaders signed a fragile deal with the ruling coalition and allies of Kabila on Dec. 31 that requires him to step down after elections that must happen by the end of 2017.
This week villagers discovered the bodies of two U.N. investigators and their Congolese interpreter who went missing this month in Kasai Central province, an area engulfed in a violent uprising.
(Reporting by Michelle Nichols; Editing by James Dalgleish)