"They want to undermine the African Union and (South African) President Mbeki's (mediation) efforts because they are racist, because they think only white people think better," said Deputy Information Minister Bright Matonga.
"It's an insult to African leaders," Mr Matonga said.
Mr Matonga insisted that Mr Mugabe, elected last month in a widely denounced one-man vote, was the southern African nation's rightful leader.
"President Mugabe is the legitimate president of Zimbabwe and no amount of force or pressure will reverse that," he said.
The leaders of the Group of Eight (G8) rich countries wound up their summit in Japan rejecting Mugabe's legitimacy and promising "further steps" against the regime over its disputed election.
Mr Matonga accused them of trying to set up a "parallel structure" to the African Union (AU), which appointed Mbeki as a regional mediator in Zimbabwe's electoral crisis....