KABUL, Afghanistan – U.S. officials say a news conference with Defense Secretary Chuck Hagel and Afghan President Hamid Karzai is cancelled because of a security threat, but the two men plan to meet privately.

The cancellation comes a day after a suicide bomber on a bicycle struck outside the Afghan Defense Ministry killing nine Afghan civilians and wounding 14 others.

U.S. officials would not provide details on the security concerns. They spoke on condition of anonymity because they weren't authorized to discuss the matter publicly.