KABUL, Afghanistan — President Hamid Karzai was vested with another five years in office… KABUL, Afghanistan — President Hamid Karzai was vested with another five years in office Monday as an Afghan election commission canceled next Saturday’s runoff and declared the incumbent the winner by virtue of the votes he gained in the first-round election in August.

The commission’s action came a day after Karzai’s challenger, former Foreign Minister Abdullah Abdullah, announced that he wouldn’t participate in the runoff because of concerns about vote fraud in the second round.

In announcing their decision, commissioners said that the Afghan Constitution called for two candidates to be in the runoff, and those conditions no longer could be met. They also cited concerns about the costs and security risks of trying to hold a wartime election that would be void of all meaning with only one candidate still in the race.

“We declare that Mr. Hamid Karzai … who is the only candidate for the second round of the election of Afghanistan in 2009, we declare (him) as elected president,” said Azizullah Ludin, the chairman of the Independent Election Commission, which is empowered to certify the winter.

The commission’s action came after several days of meetings, and consulting with lawyers about the legality of canceling the second round.

A few weeks earlier, many Afghans and Westerners here had viewed the second round as a way of producing a more credible winner than the first round, which was marred by widespread vote fraud. Western diplomats had put intense pressure on Karzai to accept a decision by the U.N.-backed Electoral Complaints Commission that voided hundreds of thousands of his votes, forcing the runoff as his tally fell below 50 percent of the valid ballots cast.

The Taliban-led insurgency planned to attack polling sites and take other actions to disrupt the second round of voting. Last Wednesday, insurgents stormed a private guesthouse where election workers were staying, and killed five U.N. workers and wounded nine.

Once Abdullah withdrew, however, Western diplomats were quick to back canceling the second round.

On Monday, the top official at the U.N. mission in Kabul, Kai Eide, endorsed the commission’s decision, as did the U.S. Embassy In Afghanistan.

“The United States welcomes the decision by the Independent Election Commission (IEC) to conclude Afghanistan’s electoral process by forgoing a second round of balloting,” a statement released by the embassy said.

Karzai campaign aides said over the weekend that the president had hoped that the second round would proceed. On Monday, Moen Marastyal, a senior Karzai campaign official, said the president would accept the election commission’s decision.

One of Abdullah’s demands for continuing with the election was for the removal of the commission’s chairman, Ludin, whom he accused of favoring Karzai.

Karzai rejected that demand, saying he didn’t have the legal authority to remove Ludin.

The commission’s decision Monday came just days before the election. Extensive preparations had been made to distribute ballots, deploy observers and marshal tens of thousands of Afghan and international security forces to help provide security.

Considerable criticism has been focused on the election commission, which oversaw the flawed voting process.

On Monday, one election commissioner, Zakria Barakzai, responded to Western reporters.

“The country was not ready. I want to say that please check your history in your countries,” Barakzai said. “Don’t compare … your experience of 100 years of conducting elections and our experiences of a few years.”

Barakzai said that there shouldn’t be a blame game, but if there were, he’d accept blame. The candidates also bore blame, however, because their backers committed fraud, he said.