Windhoek - Namibia's economy is seen weakening further this year and government revenue falling due to a global slump in commodity prices and a drought, the finance minister said.

Gross domestic product would slow to 4.3 percent in 2016 after a 4.5 percent expansion in 2015, Finance Minister Calle Schlettwein said in his budget speech.

State revenues would be 4.6 percent lower than estimates made in October's budget, the minister said.

“Mining output for some of the major commodities was weaker due to low prices and weak external demand which, together with the effects of the drought in the agricultural sector, resulted in the estimated reduction in output from the primary industries,” said Schlettwein in a document released on Friday.

Diamond and uranium mining, which contributed 13 percent to GDP in 2014, contracted 2.8 percent and 8.5 percent in 2015, the finance ministry said.

Recovery in agriculture would stall if the rainy season disappointed, with water shortages in the capital Windhoek also hurting industries such as construction and manufacturing, the finance ministry said in a statement.

Industrial output in the country was hard-hit by the worst drought to hit the southern African region in decades, as well weak global demand for commodities as major importers like China grappled with slowing growth, said the finance ministry.