Ban met with Mugabe on the sidelines of the UN food summit in Rome earlier this week and "highlighted the need to stop the violence and to deploy neutral international observers", UN deputy spokesperson Marie Okabe told AP.

While talking with Mugabe, Ban suggested sending Haile Menkerios, a Harvard-educated diplomat and former Eritrean ambassador, to Zimbabwe "to discuss ways of how the United Nations can help in the election process," Okabe said.

Mugabe agreed to Ban's request, she told the AP.

Ban now plans to send Menkerios, the UN assistant secretary-general for political affairs, to Zimbabwe within days, as soon as Menkerios obtains a visa.

The opposition and rights groups have accused Mugabe of orchestrating violence and intimidation in the run-up to the vote.

The 61-year-old Menkerios was appointed by Ban to the No. 2 political affairs job in May 2007.

He previously was deputy UN special representative in the Congo and directed one of the Africa divisions in the Department of Political Affairs.

In the 1990s, he represented the Eritrean government in varying roles as ambassador to the UN, to Ethiopia, to the Organisation of African Unity and as special envoy to Somalia and the Great Lakes region.

Menkerios would face a challenging situation in Zimbabwe, where opposition presidential candidate Morgan Tsvangirai placed first in the March elections and now faces a run-off with Mugabe.

US and British diplomats were attacked on Thursday while trying to investigate political violence in Zimbabwe and a US Embassy staffer was beaten, an embassy spokesperson said. The group was stopped at a roadblock just north of Harare.

Tsvangirai resumed campaigning on Thursday after spending nine hours in police detention on Wednesday, when he was stopped at a roadblock.