HARARE (Sapa-AFP) - Zimbabwe President Robert Mugabe met a top United Nations official Tuesday, a source close to the UN said, 10 days before a run-off election that rights groups and Western powers say is tainted by violence.

Haile Menkerios, UN assistant secretary general for political affairs responsible for Africa, arrived late Monday to evaluate the political situation in the country with violence mounting before the second round of the presidential poll.

No details of his meeting with Mugabe were disclosed.

"He (Menkerios) met with the president just before lunch," the source, who asked not to be named, told AFP.

The UN delegation held internal talks after the meeting, the source added.

Menkerios's visit, set to run through Friday, follows talks between UN chief Ban Ki-moon and Mugabe on the sidelines of a food summit in Rome earlier this month.

Ban has said he told Mugabe that "there should be no further violence and that this forthcoming presidential run-off election should be held in a most transparent, fair, competitive and credible way."

The UN chief said he also urged Mugabe to allow humanitarian aid to be delivered.

The Zimbabwean government has suspended all aid work after accusing non-governmental organisations of siding with the opposition, prompting charities to warn of a potential crisis as the country faces the world's highest inflation rate and food shortages.