|The sanctions were imposed over human rights abuses spanning more than a decade as well as election fraud [Reuters]
Zimbabwe's president has threatened to seize foreign firms and boycott their products in retaliation for Western sanctions against him and senior members of his ruling ZANU-PF party.
Robert Mugabe made special mention on Wednesday of British-controlled banks and businesses, saying they controlled 400 businesses in the former British colony in southern Africa.
"It is now time to take action," Mugabe told thousands of supporters at an outdoor rally in the capital, Harare.
"Indigenisation and empowerment should start with those companies. We must take them over. We are not ashamed of that."
The European Union and US imposed a travel ban and financial sanctions on Mugabe and his ZANU-PF allies over suspected human rights abuses spanning more than a decade as well as election fraud.
Mugabe, who insists the sanctions were imposed after he seized land belonging to white Zimbabwean farmers, said British firms and other European and American interests took out profits on mining and other ventures.
"We say no to that. If we know that some of them have products which we are buying, including foodstuffs, before we seize those companies, we can boycott their products," he said.
Mugabe has said previously ZANU-PF will nationalise firms from countries that have imposed sanctions, arguing they cannot operate freely while Western powers punish his party.
The threats heightened worries of foreign investors in the resource-rich country, which introduced a law specifying 51 per cent of firms worth over $500,000 should be owned by black Zimbabweans.
Lorries and buses carrying Mugabe supporters arrived earlier on Wednesday at an open field on the edge of Harare. The supporters sang slogans and raised Mugabe's trademark clenched-fist salute.
The political party of Morgan Tsvangirai, the Zimbabwean prime minister, boycotted the gathering.
In a statement, Tsvangirai's Movement for Democratic Change (MDC) - currently in a shaky coalition with Mugabe - said the measures against Mugabe and his ZANU-PF party resulted from its record of violence, intimidation and vote-rigging.
The statement said Tsvangirai distanced himself from the "unpopular and bloodthirsty" party, referring to the ZANU-PF.
The 87-year-old Mugabe, in power since independence from Britain in 1980, says Western sanctions have destroyed Zimbabwe's economy, although critics and economists blame his violent land distribution programme for crippling the country's agriculture industry since 2000.
Barack Obama, the US president, extended on Wednesday for one year the Bush-era sanctions against individuals closely linked to Mugabe. The sanctions had been scheduled to end on March 6.
"While some advances have been made in Zimbabwe, particularly on economic stabilization, since the signing of the power-sharing agreement, the absence of progress on the most fundamental reforms needed to ensure rule of law and democratic governance leaves Zimbabweans vulnerable to ongoing repression and presents a continuing threat to peace and security in the region and the foreign policy of the United States," Obama said in a statement to the US congress.
"Politically motivated violence and intimidation, and the undermining of the power-sharing agreement by elements of the Zimbabwe African National Union-Patriotic Front party, continue to be of grave concern."