KABUL, Afghanistan — U.S. Defense Secretary Chuck Hagel’s scheduled news conference with Afghan President Hamid Karzai in Kabul Sunday was canceled due to security reasons, according to two U.S. officials.

Hagel still plans to meet later Sunday with Karzai, the officials told reporters in Kabul, asking not to be identified because they weren’t authorized to discuss sensitive security issues. Pentagon spokesman George Little declined to provide any details on the cancellation.

Hagel, who arrived in Kabul on Friday, is making his first international trip as the top U.S. defense official to prepare for what he’s called a “responsible transition” in the Afghan war. Saturday, suicide bombers struck in Kabul and Khost, killing 19 people.

The Taliban, who claimed responsibility for the Kabul attack, is holding peace talks daily with the U.S., Karzai said Sunday in an e-mailed statement. The negotiations are going on “in Gulf and European countries,” Karzai said.

His comments are “completely untrue” and “no talks are ongoing,” Taliban spokesman Zabihullah Mujahed said by e-mail.

Karzai also said that Saturday’s suicide bombings “were in the service of America.” The Afghan president’s assertion that the U.S. and Taliban are in collusion is “categorically false,” U.S. Marine Corps Gen. Joseph Dunford, commander of NATO forces in Afghanistan, told reporters in Kabul Sunday.