Addressing supporters at the burial of a senior government official, Mugabe said his ZANU-PF party regarded black economic empowerment as a key part of the national liberation struggle, dismissing fears it would hurt economic recovery.
"We are not stopping," he said to cheers.
"So we are saying we must take over our country and those partners, those outsiders, who want to work with us must do so as junior partners. We are the senior partners, no more the junior partners," he said.
"Those who also want to work for us, they are welcome."
Mugabe has said previously ZANU-PF will nationalize firms from countries that have imposed sanctions on Zimbabwe, arguing they cannot operate freely while Western powers punish his party over charges of rights abuses.
These threats have added to the worries of foreign investors in the resource-rich country, which has introduced a law specifying 51 percent of firms worth over $500,000 should be owned by black Zimbabweans under a five-year programme.
"We are not afraid to declare our programme publicly. We are saying very openly, ‘Britain and America, this is our country and we have a right over its resources and we are taking control now’," Mugabe said.
Mugabe — who has seized and distributed white-owned commercial farms to landless blacks under the banner of correcting colonial injustices — said it was futile to appease "imperialist" Western powers, mentioning Libyan strongman Muammar Gaddafi.
"Look at what they are doing to Gaddafi. He tried to appease them by giving them access to (oil) resources, by investing money with Western financial institutions but they have turned on him," he said of his former political ally.
Mugabe, who was forced into a unity government with rival Prime Minister Morgan Tsvangirai’s Movement for Democratic Change two years ago to try to ease a severe economic crisis blamed on his policies, is pushing for an early general election this year before agreed democratic reforms.
MDC officials have said Mugabe’s call for an election this year would devastate a nascent recovery in Zimbabwe, whose economy has been devastated by hyperinflation.
Analysts say years of mismanagement by Mugabe and ZANU-PF caused the economic woes, but Mugabe, 87, who has been in power since independence from Britain in 1980, has laid the blame in large part on financial sanctions on Zimbabwe.
On Sunday, Mugabe made no reference to his election plans or to growing tension between ZANU-PF and the MDC over political violence, the cancellations of opposition rallies and the arrest of MDC officials on what the party sees as trumped-up charges.