Global pressure continues to mount Sunday on Afghan President Hamid Karzai to accept a possible runoff in Afghanistan's disputed election.

Afghan President Hamid Karzai (file photo)Senior foreign officials have urged Mr. Karzai to accept the findings of a fraud investigation by a U.N.-backed panel that could decide whether the nation's disputed election goes to a runoff.

French Foreign Minister Bernard Kouchner, U.S. Senator John Kerry and former U.S. Ambassador to Afghanistan Zalmay Khalilzad met with Mr. Karzai in Kabul Saturday ahead of the long-delayed announcement by the Electoral Complaints Commission (ECC).

Senator Kerry said, in an interview with CNN, it would be irresponsible for the United States to send more troops to Afghanistan when the outcome of the Afghan election is not clear.

Abdullah Abdullah (File photo)Preliminary results released last month gave Mr. Karzai 54 percent of the vote. His main challenger, former Foreign Minister Abdullah Abdullah, had 28 percent. But if the EEC discards enough ballots to drop Mr. Karzai's total below 50 percent, a second round of voting will be necessary.

In other developments, NATO says a U.S. soldier was killed during a bomb attack in southern Afghanistan Sunday. No further details were released.

NATO says that on Saturday, several militants were killed and captured during search operations by Afghan and international security forces in Khost and Ghazni provinces.

And in another incident, NATO says Afghan and NATO-led troops killed a small group of militants and wounded several others during an operation Friday. It says the operation was aimed at detaining an insurgent leader in southern Uruzgan.

The joint force also killed one militant and detained several others during an incident Friday in Helmand province.

Some information for this report was provided by AFP, AP and Reuters.