DRC must hold a long-delayed election to replace President Joseph Kabila by the end of next year or the vote will lose international support. File picture: Reuters

Kinshasa - Democratic Republic of Congo must hold a long-delayed election to replace President Joseph Kabila by the end of next year or the vote will lose international support, the U.S. ambassador to the United Nations said on Friday.

Repeated delays to the poll, originally scheduled for late 2016, have fuelled surging political tensions in the Central African nation and raised fears the country could slip back to the wars of the turn of the century that killed millions.

US envoy Nikki Haley, who met with the Congolese electoral commission (CENI) during a visit to Kinshasa, told reporters she had passed on a message that "these elections must take place in 2018 or there will be no support for the electoral process."

The electoral commission had said earlier this month that the vote to replace Kabila could not take place until April 2019 at the earliest, leading the opposition to warn that the population would "take matters into its own hands".

"The US will not support anything in 2019. The international community will not support anything in 2019," Haley said.

Haley, who is wrapping up a week-long trip to Ethiopia, South Sudan and Congo, was scheduled to meet Kabila later on Friday. Kabila has ruled Congo since his father's assassination in 2001.