UNITED NATIONS - The United Nations, criticized over fraud in Afghanistan's presidential elections last year, cannot back future polls without reforms to the voting process, U.N. chief Ban Ki-moon said in a new report.

Corruption, violence and voter intimidation marred last August's vote. After a partial audit of results, a second round was set between President Hamid Karzai and challenger Abdullah Abdullah, but Abdullah pulled out, leaving Karzai the victor.

A report on Afghanistan by Ban to the Security Council, made public on Monday, admitted the flaws turned the elections into a political crisis, sapping confidence in the Afghan leadership and international will to engage in the country.

The United Nations provided financial and technical support to the Afghan government-appointed Independent Election Commission (IEC) and also nominated three of the five members of the Electoral Complaints Commission (EEC).

But, the U.N. secretary-general said, the process revealed serious flaws and weaknesses that need to be corrected before the United Nations can engage in a similar supporting role for future elections.

The election commission announced on Saturday that parliamentary elections would take place on May 22.

Among reforms Ban said were needed were a review of the appointment mechanism for the IEC to ensure its impartiality, improvements to the voter registration system, development of domestic observation and strengthening of the legal framework.

The August election row led to a split within the U.N. mission in Afghanistan itself after its deputy head, American Peter Galbraith, accused his Norwegian boss Kai Eide of failing to deal firmly with fraud. Galbraith was fired in September.

GLOOMY ATMOSPHERE

Ban said the election saga, along with the increasingly violent struggle against Taliban insurgents, had contributed to a gloomy atmosphere in Afghanistan. If the negative trends are not corrected, there is a risk that the deteriorating overall situation will become irreversible, he said.

We are now at a critical juncture. The situation cannot continue as is if we are to succeed in Afghanistan, the U.N. chief said. There is a need for a change of mindset in the international community as well as in the government.

Ban added his voice to calls by the United States and others for a civilian surge to match a stepped up military drive against the Taliban, to improve political and development efforts.

He called for a dedicated civilian structure, but said this must involve Kabul and be co-chaired by an Afghan minister and by the U.N. special envoy -- currently Eide, although the Norwegian is due to be replaced in March.

Ban also said Eide supported appointment of a top civilian official by the NATO-led International Security Assistance Force in Afghanistan, although some U.N. officials have voiced concerns that such a figure could overshadow the U.N. envoy.

Eide is due to address the Security Council later this week, U.N. spokesman Martin Nesirky said.

Western diplomats say two leading candidates to replace Eide are Swedish diplomat Staffan de Mistura, a former U.N. special envoy to Iraq, and Jean-Marie Guehenno of France, who ran the U.N, peacekeeping department from 2001 to 2008.

In an unusual move, the New York Times ran an editorial last Friday endorsing Guehenno.

Ban's report also painted a bleak picture of the security situation in Afghanistan, noting an average of 1,244 violent incidents per month in the third quarter of 2009, a 65 percent increase over the previous year.

There were 784 conflict-related civilian casualties between August and October, a rise of 12 percent over the same period of 2008, and insurgents assassinated an average of nine people per week in the third quarter, he said.

(Editing by Cynthia Osterman)

Elections Afghanistan