Zimbabwe's long-serving president Robert Mugabe has threatened to expel foreign-owned companies over what he said was the west's interference in the politics of the country he has led since 1980.

Mugabe said on Sunday he wanted no "ideas from London or Washington", speaking before supporters at the funeral of a military chief in Harare.

He warned the west that although his government had not "done anything to your companies, time will come when we will say tit for tat".

He said: "You hit me, I hit you. We have a country to run and we must be left free to run it."

Britain, the former colonial power, the European Union and the US have refused to endorse Mugabe's landslide victory in the 31 July elections, citing evidence of vote-rigging. The west maintain economic restrictions on Mugabe and leaders of his ruling party.

Mugabe insists his party won "a resounding mandate" in the last election and denies allegations of voting fraud.

Zimbabwe's state election panel said Mugabe won the elections with 61% of the presidential vote.

Mugabe, who was sworn in on Thursday for another five-year term at the age of 89, said "there will come a time when we lose our patience" with the west's pressure for democratic reforms.

"I want to assure you our attitude will not continue to be passive," Mugabe said Sunday. "We have had enough and enough is enough."

Since winning another term, Mugabe has vowed to push ahead with a black empowerment programme to force foreign and white-owned businesses to cede 51% ownership to black Zimbabweans. Some economists warn that the programme will trigger another economic downturn similar to that Zimbabwe suffered after Mugabe's government seized white-owned farms in 2000.

Mugabe, however, says the economic plan to force black control of companies will create jobs and economic growth that had been hindered by what he called "a tenuous and fraught coalition with uneasy partners" in the opposition led by former prime minister Morgan Tsvangirai.

Tsvangirai had favoured attracting western investment during the five-year coalition forged by regional leaders after the last disputed elections in 2008.

Mugabe says Britain has opposed black empowerment since he forced thousands of white farmers to surrender their land. Critics of the programme say it disrupted Zimbabwe's agriculture-based economy, shut down industries and scared away foreign investment in mining and other businesses.