KABUL - U.N. Secretary-General Ban Ki-moon made a surprise visit to Afghanistan on Monday, a day after the only challenger to President Hamid Karzai withdrew from next week's runoff election.

The arrival of the world body head comes as international diplomats are driving for a quick resolution to the country's troubled election after top challenger Abdullah Abdullah pulled out of the race Sunday.

Abdullah's withdrawal effectively handed Karzai a victory, but it is still unclear if the vote will go forward Saturday as scheduled. The two had been in talks about a power-sharing deal, and negotiations could still be going on. Abdullah chose not to boycott the vote, a conciliatory move that could mean he is still hoping for a deal.

U.N. Continuing Support

The United Nations said Ban will meet with the two men "to assure them and the Afghan people of the continuing support of the United Nations toward the development of the country."

A deadly attack on a Kabul guest house with U.N. election workers last week has raised questions about whether the U.N. might scale back in Afghanistan.

The U.N. kept operating after an August 2003 truck bombing at its headquarters in Baghdad, which killed 22 people, including mission chief Sergio Vieira de Mello, but after a second bombing it shut down operations in Iraq in late October 2003 for years.

Ban will also meet with U.N. staff and security officials, the statement said.

Government's Credibility

It has been more than a month since the Aug. 20 balloting that aimed to strengthen the Afghan government but instead undermined its credibility both at home and with key allies like the United States.

The vote was characterized by rampant ballot-box stuffing, and fraud investigators threw out nearly a third of Karzai's votes.

That move dropped Karzai below the 50 percent threshold needed to win outright, forcing the runoff vote.

---

© 2009 The Associated Press. All rights reserved.