Kenya's revenue from its tourism sector dropped 2.9 percent last year to KES84.6 billion shillings (USD$837.2 million).

Visitor numbers and earnings have dropped in the past four years as al Shabaab militants from Somalia launched attacks on Kenyan soil in retaliation for Kenya's military intervention.

Showing the depth of the fall, tourist arrivals fell from 1.8 million in 2011 to 1.18 million last year. The country earned KES98.9 billion shillings in 2011 compared with the KES84.6 billion shillings last year.

Najib Balala said the sector was on course for a recovery in 2018, in line with government plans, but cautioned that violent protests against the country's electoral body could curb arrivals.

"A lot of people I meet are saying Kenya is maturing but when they see the incidents of the last weeks, they say we are going backwards," he said.

"My concern is that, the efforts and the road map is working very well, I don't want the political noise to interrupt that."

Tourism is one of the main hard currency earners for Kenya.

President Uhuru Kenyatta's government wants to bring in 3 million visitors a year according to its manifesto when it was elected in early 2013.

Efforts to revive the sector include boosting security, opening new source markets such as Nigeria and Poland and increased budgetary allocations to the sector.

Visitors are expected to rise by a third this year to 1.6 million and to recover to 1.8 million in 2018, matching a record high set in 2011.