Zimbabwe's opposition leader Morgan Tsvangirai rejected calls on Tuesday for a national unity government instead of a presidential runoff vote and said his party was sure to win the election despite government violence.
Tsvangirai told a news conference Zimbabwe had suffered a de facto coup and was being run by a military junta.
Some 66 supporters of his Movement for Democratic Change (MDC) had been killed since disputed March elections, he said.
Simba Makoni, a defector from the ruling ZANU-PF party and a former finance minister, said earlier the June 27 run-off between President Robert Mugabe and Tsvangirai must be called off because a free and fair vote was impossible.
"Following the announcement of the date for the run-off, no one can change that due process unless Robert Mugabe concedes defeat, or collapses. It therefore means that a government of national unity negotiated before the runoff does not arise," Tsvangirai said.
U.S. Secretary of State Rice was consulting other countries to see what practical steps could be taken by the international community to ensure a real runoff election.
"We're continuing to focus on trying to make this runoff election one that can be as free and fair as possible, that will reflect the will of the Zimbabwean people. Whether or not that can happen is an open question," U.S. State Department spokesman Sean McCormack added.
HUMAN RIGHTS WATCH
U.S.-based Human Rights Watch also said brutal intimidation and murder by Mugabe's supporters made normal campaigning impossible.
"As a people we have been exposed to state-sponsored brutality. The violence continues unabated," Tsvangirai said.
He said 3,000 MDC supporters had been injured and more than 25,000 displaced but the MDC would win even if ZANU-PF prevented them campaigning.
"As far as I am concerned I can stay home from now on until the election, Mugabe will lose. It's just a formality to go and campaign, the people have already decided."
An EU-U.S. summit in Slovenia on Tuesday called on the Zimbabwe government to end what it called state-sponsored violence and urged U.N. Secretary-General Ban Ki-moon to send monitors to deter further violence.
