Botswana saw its diamond sales plunge by more than 70 percent in the second half of 2011 to $160.3 million (122 million euros), Finance Minister Kenneth Matambo said Wednesday.

Presenting the 2012-2013 national budget, Matambo said 2011 economic growth was expected to come in at 5.1 percent and forecast 4.4 percent growth in 2012.

He warned that no quick improvement was in sight for the country's top export and that it could force the government to reconsider its spending plans.

"There is no guarantee that this trend will be reversed in the near future unless the situation improves in the USA and the euro area," said Matambo.

"Current projections indicate that the volume of diamond sales in 2012 will be almost equal to those for 2011. Should this forecast come true, we will be forced to re-prioritise our planned expenditure options both at national and individual household levels in light of a constrained budget and economic outlook."

Matambo said the economy would get a boost this year from the launch of the 600-megawatt Morupule B coal-fired power project, designed to end Botswana's dependence on electricity imports.

But he warned that if the global economy experienced a double-dip recession, quick recovery in the debt-laden domestic economy could prove difficult.

"We all have to be prepared to make sacrifices," he said.

Botswana could be facing job cuts in the public sector after the International Monetary Fund last year told the government to slash its wage bill, saying it was too big a slice of the economy and was hurting competitiveness.