America's ambassador to Zimbabwe says there is little the international community can do to stop President Robert Mugabe from going ahead with this Friday's run-off election despite growing concern about Mugabe's policy of intimidation against his political rival.

"There's really nothing that we can do in the international community to stop these elections," James McGee said in a conference call to reporters.

McGee said officials at the U.S. embassy believe Mugabe supporters will force citizens to vote and will use violence if necessary.

On Tuesday, Mugabe adamantly declared the vote would go ahead.

"He (Movement for Democratic Change Leader Morgan Tsvangirai) now says he wants to negotiate. We say we won't refuse to negotiate but for now there is only one thing for us to accomplish ... it's the legal process on the 27th of June," Mugabe said Tuesday in western Zimbabwe.

Tsvangirai won the first round of the presidential vote on March 29, but didn't capture more than 50 per cent of the votes needed to win the presidency.

He has been holed up in the Dutch embassy in Harare since Sunday night, after saying he would pull out of Friday's run-off against Mugabe, who has been president since 1980. Reports say Tsvangirai was fleeing government soldiers who were on their way to his home.

Tsvangirai has told Dutch radio he will leave the embassy within the next 48 hours.

On Monday, the United Nations Security Council condemned the situation in Zimbabwe.

"The Security Council regrets that the campaign of violence and the restrictions on the political opposition have made it impossible for a free and fair election to take place on June 27," said the watered-down final version.

Britain's original draft explicitly blamed the Mugabe regime and said Tsvangirai would be the legitimate leader if a proper run-off vote couldn't be held.

"I think it's a very important resolution. It recognizes the people who are accountable for the violence and it squarely placed that responsibility at Mugabe's leadership," Tsvangirai told Dutch radio.

South Africa -- Zimbabwe's influential neighbour, which has advocated "quiet diplomacy" -- pronounced itself pleased with the statement, saying it "assists us in the mediation."

Canada's Foreign Affairs and International Trade Minister David Emerson also endorsed the UN resolution in a press release issued on Tuesday night.

"We agree fully with the content of this statement, including the conclusion that the results of the March 29 elections must be respected," Emerson's statement said.

"The Government of Zimbabwe will not be legitimate without a free and fair vote."

Emerson appealed to Zimbabwe's ruling party to discontinue its campaign of intimidation against its political foes.

"It is clear that the alarming campaign of human rights violations and politically motivated violence, committed largely by state security and paramilitary groups, aims to intimidate opposition supporters and discourage them from voting," the statement went on.

"This, combined with the arrests of key opposition leaders, the prohibition on opposition political rallies, and the ban on opposition advertisements on state media, have contaminated the electoral environment."

Emerson's statement then called on the leaders of neighbouring African countries to help mediate an end to the political conflict.

Although South Africa's President Thabo Mbeki has resisted calls to use economic pressure on Mugabe, African National Congress leader Jacob Zuma is calling for regional and UN intervention.

"The situation in Zimbabwe has gone out of hand, out of control... We cannot agree with what (the ruling) ZANU-PF is doing at this point in time," he said.

Reuters reporter Nelson Banya told Canada AM from Harare on Tuesday that it doesn't appear that Mugabe will bend to the growing international diplomatic condemnation.

However, there's word Mbeki might visit Zimbabwe before Friday's vote, and there may be some other regional diplomatic efforts, he said.

Senegal's President Abdoulaye Wade has been trying to mediate the political crisis, and said he had hoped to convince Mugabe to share power with Tsvangirai.

"I can say that this objective has been almost completely snuffed out since I have learned that soldiers went after Morgan Tsvangirai at his residence on Sunday," Wade said.

A Zimbabwe police official told a news conference in Harare that neither Tsvangirai nor his Movement for Democratic Change party had reported any threats.

"Mr. Morgan Tsvangirai is under no threat at all from Zimbabweans and he should cast away these delusions," Augustin Chihuri said.

However, the MDC said a chair of one of its provincial organizations was attacked Tuesday by men in military uniform. As well, the elderly father of the party's national organizing secretary was beaten and two other relatives were shot in the legs.

Tsvangirai himself has been detained at least five times by Zimbabwean authorities. Tendai Biti, the MDC's second in command, is in jail facing a treason charge.

Tsvangirai claims that 86 of his supporters have been killed and 200,000 left homeless as a result of violence from supporters of Mugabe's ZANU-PF party.

With files from The Associated Press