This week Zimbabwe's diamond industry was saved from a ban by the 70-member global diamond trading group as a result of a campaign from human rights organisations. The Mugabe government is being accused of killings in the Murange diamond fields last year. While countries participating in the Kimberly process - which outlaws trade in conflict diamonds - rejected an outright ban it was a close call and reflects the sort of pressures that the Harare government continues to face.

Mr Mugabe is in a coalition with Mr Morgan Tsvangirai's Movement for Democratic Change - what one observer called a "marriage of inconvenience" consummated after Mugabe refused to leave when Tsvangirai beat him to the ballot in 2008.

The fight between Mr Mugabe, who has attracted a host of sanctions and condemnations from Western countries, and Mr Tsvangirai is something of a proxy war. MDC has massive goodwill in the West and has been accused of frustrating the government of national unity. Mr Mugabe supporters see MDC has a stooge and its presence in cabinet as the presence of Western interests.

Nonetheless addressing a meeting in Washington on US President Obama's top Africa diplomat Johnnie Carson who has served in Zimbabwe, Kenya and Uganda was adamant that pressure would not eased.

Mr Carson has also cracked the whip in Kenya where personal sanctions including a travel ban on Kenya's long time Attorney General Amos Wako have been imposed.