The steady decline in crude oil prices from 2014 peaks above $100 per barrel has left lasting impacts on the economy of OPEC-member Angola, the International Monetary Fund said.

Angola is one of the lesser producers in the Organization of Petroleum Exporting Countries, accounting for less than 1 percent of the total output from the group. Oil supports about 45 percent of the nation's economy and nearly all of its exports.

An assessment from the IMF found the decline in crude oil prices since 2014 caused severe damage to the Angolan economy.

"Fiscal revenue and exports fell substantially, economic growth came to a halt, and inflation accelerated sharply to levels not seen in over a decade," Ricardo Velloso, the IMF division chief for Angola, said in a statement.

Angola, under the terms of a managed decline agreement from OPEC, committed to cut about 78,000 barrels per day from production starting next week. That would put the country's production level at about 1.67 million barrels per day based on the agreement. Angola reported total crude oil production to OPEC for November was 12 percent higher than the previous month.

Velloso said Angolan financiers needed to put more emphasis on non-oil revenue in an effort to diversify an economy that's highly exposed to shocks that accompany volatility in the crude oil market. According to the IMF, authorities in Angola have taken steps to offset the risks from lower oil prices, though additional efforts are necessary.

Economic growth for Angola is expected at 1.25 percent next year, compared with no growth this year. That shows economic planners have made progress on the non-oil front, though inflation is projected at around 45 percent.

"Over the medium term, the outlook is for a gradual recovery in economic activity, but there are risks, including a further decline in oil prices and delays in implementing the needed structural reforms to promote economic diversification," the IMF reported.