Botswana's relations with Zimbabwe are becoming strained after Botswana began erecting a security fence along its north-eastern border with Zimbabwe.
Zimbabweans face queues for almost everything nowadays
Zimbabwean high commissioner to Botswana, Phelekezela Mphoko, is reported by South Africa's state broadcaster to have branded the move as provocative.
Earlier this year the government decided to erect a four metre-high electric fence along the 500km border shortly after an outbreak of foot and mouth disease in that area.
But the government has also been coming under growing pressure within Botswana to stem the flow of illegal immigrants crossing the border to flee the political and economic crisis in Zimbabwe.
Prof Malima, a journalist for South Africa's Business Day newspaper in the capital, Gabarone, says that the Botswana Government is repatriating about 2,500 Zimbabweans each month.
"It is costing the government quite a lot of money," he told the BBC's Network Africa.
Botswana's beef industry, which is the country's second highest earner after diamonds, was hit badly by the foot and mouth crisis.
"Last year they had to put down thousands of animals and it affected exports badly,"
He said the perception in Botswana was that Zimbabwe's Government was unable to prevent the influx of cattle or people.
Apart from food shortages affecting millions of Zimbabweans, the country is struggling with a widespread cash shortage, inflation of almost 400%, unemployment of about 70% and fuel shortages.
Zimbabwe's main opposition party blames President Robert Mugabe for the mismanagement of the economy during his 23-year rule.
But Mr Mugabe blames international opponents for sabotaging the economy because of his controversial policy of seizing white-owned farms.
Regional efforts to halt the flow of Zimbabweans leaving the country and to resolve the political crisis have made little progress so far.