Botswana’s President Ian Khama on Thursday said the government cannot afford to give the striking public service workers the 16 percent salary increase they are demanding.

Addressing a high-level consultative council, Khama who has been silent since the strike began on April 18, said government spending remained in deficit with a projected revenue shortfall of seven billion pula ($1.057 billion) in the current financial year.

"A 16 percent wage increase would thus add nearly two billion pula more to the budget deficit, in the absence of deep cuts elsewhere," said Khama.

He said that public sector wages already cost the government 12 billion pula annually, considerably more than the 10 billion pula allocated for development this year.

The strike, which is the country's worst labour action, has shut down schools and hospitals.

"The salary increase which we are offering can therefore be implemented if government stays within its budget projections," he said.

Botswana, the world's top diamond producer, was hard hit by the global economic crisis which resulted in a sharp decline of sales.

Khama said the country's economy was still volatile, due to internal and external developments, such as rising fuel prices and the recent earthquake in Japan.

He mentioned that unlike many other countries burdened with budget deficits Botswana had not cut public sector salaries or jobs.

"It is regrettable that this fact is not appreciated by those on strike. I will not take any decision that would drive the country in debt. One cannot give what one does not have," he said.

This week, the government fired all "essential" health workers who defied a court order to join the strike, forcing the country's biggest hospital, Princess Marina to shut down.

Civil servants who have not had a salary increase for the past three years are demanding a 16 percent raise.

Khama confirmed that government had offered unions an unconditional three percent increase, down from an initial five percent offer.