U.N. Secretary-General Ban Ki-moon is calling on Zimbabwe's government to postpone Friday's planned run-off presidential election, saying a vote held in the current conditions would lack all legitimacy. From United Nation's headquarters in New York, VOA's Margaret Besheer has more.

Mr. Ban called on President Robert Mugabe to halt the violence and intimidation that has gripped the country in the wake of the contested March 29 presidential elections.

The secretary-general said conditions do not exist right now for a free and fair vote, and urged the authorities to postpone Friday's planned run-off election, saying it would only deepen divisions within the country.

"There has been too much violence; too much intimidation," he said. "A vote held in these conditions would lack all legitimacy."

On Sunday, President Mugabe's political rival, Morgan Tsvangirai, announced his withdrawal from this week's run-off election, saying violence against his supporters made the poll impossible. He has since sought refuge at the Dutch embassy in Harare.

Secretary-General Ban says he has spoken with a number of African leaders who also agree that the poll must be postponed. He urged regional organizations to use their leadership to bring peace and stability to Zimbabwe, saying the situation has broad, regional implications.

"The situation in Zimbabwe represents the single greatest challenge to regional stability in southern Africa today," he said. "The region's economic and political security are at stake, as is the very institution of elections in Africa."

The U.N. Security Council is meeting late Monday to discuss Zimbabwe, and will be briefed by the U.N. Chief of Political Affairs.

The council has been divided internally on whether to get involved in the post-election crisis.  Most notably, South Africa - which is helping to mediate the situation - has wanted to keep the issue out of the council, arguing that elections are an internal matter.

France's U.N. Ambassador Jean-Maurice Ripert, said he expects the council meeting to be "tense", but that members realize Zimbabwe's crisis is no longer an internal matter, but one that threatens regional peace and stability.

"It is obvious that nobody believes it is an internal problem of Zimbabwe anymore - even the people who are most reluctant, let's say, for the Security Council to deal with the situation - recognize that the situation now is out of hand," he said.

U.S. Ambassador Zalmay Khalilzad, who holds the rotating presidency of the council this month, said ahead of the meeting that he hopes the council will agree to a strong statement assigning responsibility for the crisis to the Zimbabwean government.