Secretary of State John Kerry slammed Iranian Supreme Leader Ali Khamenei's speech last Friday — in which he vowed his country's policy against the "arrogant" United States would not change — as "disturbing."

In an interview with Saudi-owned network Al Arabiya, Kerry said he would take Khamenei's comments, which came three days after Iran and the six world powers agreed on a long-term nuclear deal, at face value.

"I don't know how to interpret it at this point in time, except to take it at face value, that that's his policy. But I do know that often comments are made publicly and things can evolve that are different," Kerry said in the Monday interview. "If it is the policy, it's very disturbing, it's very troubling, and we'll have to wait and see."

Khamenei also said Iran would continue to support its friends in the region despite the nuclear deal, including "the oppressed Palestinian nation, Yemen, Syria, Iraq [and] Bahrain" and groups like Hezbollah.

"Our policy toward the arrogant U.S. government won't change at all," Khamenei said in the Friday speech, which also marked the end of Ramadan, the Islamic holy month. "We have no negotiations with America about various global and regional issues. We have no negotiations on bilateral issues."

Kerry is scheduled to travel to the Gulf region early next month to discuss the nuclear deal. He added that the U.S. is "very attentive to guaranteeing the security of the region."

"We are not kidding when we talk about the importance of pushing back against extremism, against support for terrorism and proxies who are destabilizing other countries. It's unacceptable," he said.