Tsvangirai's supporters have been the target of recent political violence in Zimbabwe. He said the election should be supervised by an electoral commission to ensure the will of the people is heard, The Washington Post said Saturday.

"We will contest the runoff, and the people will finally prevail," Tsvangirai said in Pretoria, South Africa. "The people have spoken before, and the people will speak again. I am ready, and the people are ready for the final round."

The Movement for Democratic Change opposition group claims that Tsvangirai defeated President Robert Mugabe in the March 29 election by an outright majority. The group said that majority meant a second round of elections would be unnecessary.

However, the electoral commission said the opposition leader did not win by a large enough percentage, making a runoff election a necessity, The Post reported.