Addressing an annual conference of his ZANU-PF party, Mugabe also said he would also press ahead with a drive to force foreign-owned firms including mines and banks to sell majority shares to local black people.
Mugabe, 88, one of Africa's longest-serving rulers and accused of hanging on to power through vote-rigging, has called for an election in March in the southern African country.
But coalition partners including Prime Minister Morgan Tsvangirai, Mugabe's old rival, first want a new constitution and electoral and media reforms after a violent and disputed poll in 2008 that was condemned by much of the world.
Mugabe told party members he would not wait forever to call elections, putting pressure on Tsvangirai's Movement for Democratic Change (MDC).
"If they do not (agree), I am going to declare sooner or later the day of an election," he said, to applause. "Enough is enough. We cannot continue to drag our feet on this."
However Finance Minister Tendai Biti, secretary general of the MDC, told Reuters that Zimbabwe would not be ready for a presidential election until at least June because it needed the reforms to ensure a fair and undisputed poll.
"It's impossible to have an election in March," he said during a visit to Manchester, England, on Thursday. He said the new constitution and reforms were needed first to ensure the poll result was "credible, legitimate and sustainable".
ZANU-PF is expected to endorse Mugabe as its presidential candidate in elections which must be held by next September, under a power-sharing deal agreed after the 2008 poll, despite his advanced age, reported ill health and disastrous economic record.
ZANU-PF and the MDC are haggling over presidential powers in the new constitution. Mugabe accused his opponents of delaying tactics to avoid elections.
Mugabe has run the former British colony since independence in 1980 but is facing increasing questions about his health.
He has travelled to Singapore several times in the last two years for medical treatment. In April his aides angrily denied reports he was fighting for his life in a Singapore hospital.
Mugabe showed no visible signs of ill-health on Friday, spending more than an hour at the podium in front of 5,000 delegates inside a new Chinese-built conference centre outside the central city of Gweru.
Mugabe, who wore a yellow shirt printed with his face and a yellow baseball cap, said black local ownership rules for foreign investors applied across the board.
"Even our Chinese friends, we are saying to them: 'In your country we do not just come'. They have to respect the rules here," he said.
Analysts say Mugabe's March election call is meant to keep his supporters ready for battle although some senior ZANU-PF officials have cast doubt on this timeline, given that a referendum on a new constitution should also precede any election, under the power-sharing deal.
A referendum on the new charter, which has been delayed by two years, is only likely in the first quarter of next year.