An election runoff between President Robert Mugabe and opposition leader Morgan Tsvangirai will be held June 27, the electoral commission said in an announcement published Friday.
The opposition, which wanted a May 23 runoff, said the decision to extend the deadline for holding the vote was "irresponsible."
Tsvangirai claims he won the March 29 presidential race outright, but official results released May 2 show he did not win enough votes to avoid a second round against Mugabe.
Tsvangirai said setting a date for June 27 was illegal but that "we will contest."
"This is a regime which operates not on the basis of the law, but operates on the basis of impunity from the law. So they are changing goal posts to suit themselves," he told reporters in Belfast, Northern Ireland, where he was attending an international conference of liberal party members.
The Zimbabwe Electoral Commission extended the deadline for holding the runoff to 90 days — beyond the legally required 21 days.
Commission: 'More time'
The commission chairman said in an interview published Friday with the Herald newspaper, a government mouthpiece, that the commission needed "substantial" resources.
"The runoff is a full election and just as big as any general election," the paper quoted George Chiweshe as saying. "Some of the resources were depleted during the first election, so we need more time to prepare for the runoff."
The opposition as well as local and international human rights groups have accused Mugabe's party of using delays to mount a campaign of violence and intimidation against opposition supporters.
Tsvangirai's Movement for Democratic Change said Thursday the postelection violence was intensifying, and that 33 of its supporters and activists already had been killed.
"This country cannot afford 90 days" of more violence and economic instability, the party's secretary-general, Tendai Biti, told reporters Thursday in Johannesburg, South Africa.
Biti and Tsvangirai have been out of the country since shortly after the March 29 vote.
Biti indicated Tsvangirai would be back in Zimbabwe for a planned campaign rally this weekend, as well as a caucus of members elected to parliament. Biti said he would return some time after Tsvangirai.
Tsvangirai's party won control of parliament in legislative elections held alongside the presidential vote. It was the first time since independence in 1980 that Mugabe's party lost control of parliament.
Half-billion-dollar bank note
On Thursday, Zimbabwe's central bank unveiled a new half-billion Zimbabwean dollar bank note.
The new bill and three others for 5 billion, 25 billion and 50 billion Zimbabwe dollars, called "special agro" checks intended for purchases and sales involved in farm production, were going into circulation next Tuesday, the central bank said.
Earlier this month, the bank floated the local currency exchange rate through commercial banks, where a single U.S. dollar sold Wednesday for around 240 million Zimbabwe dollars, slightly higher than the dominant black market rate for hard currency.
That change saw prices of goods soar, with unofficial estimates putting annual inflation at more than 700,000 percent.
Official inflation was given in February at 165,000 percent, and no further official figures have been released.
"Prices are now doubling every week instead of every month, and it is hard to see how we can survive to the end of June or how an election will be feasible at all if things continue to deteriorate at this pace," Harare economist John Robertson said.
The central bank said the "agro" checks, similar in appearance to the nation's existing range of bills, will be accepted by retailers and banks up to the end of the year.
The previous highest denomination bill was for 250 million Zimbabwe dollars, enough to buy about two loaves of bread.