Afghan President Hamid Karzai’s speech at Kansas State University scheduled for later this month has been postponed indefinitely, the university announced Monday.

Karzai’s lecture, originally scheduled for either Sept. 26 or Sept. 27, was called off because of conditions in Afghanistan, said Charles Reagan, chairman of the Landon Lecture Series. Reagan said Karzai has to cut short his visit to the United States and return home after giving a speech to the U.N. on Sept. 23.

Karzai’s Landon Lecture would have been the first time an elected president of Afghanistan spoke at Kansas State. No alternate date had been set, Reagan said.

Reagan also said the university will reschedule an address by Chinese Ambassador H.E. Zhou Wenzhong, whose Landon Lecture was scheduled for Oct. 10. Reagan said he expects the ambassador to speak later in October.

“When you are inviting speakers of this caliber, there are risks that they may not be able to come as scheduled,” Reagan said. “We prefer to take these risks in order to continue to invite the high caliber of speakers who have graced the Landon podium.”