NEW YORK (JTA) — A Twitter account believed to be run by Iran’s supreme leader, Ayatollah Khamenei, referred to the failure of “arrogant” powers to thwart Iran’s nuclear efforts.

The message was posted to the English-language account on Tuesday following the previous day’s announcement that Iran and six world powers agreed to extend negotiations on Iran’s nuclear program until June 30.

“In the #nuclear issue, arrogants have made their best to bring #Iran to its knees but they were not able and will not be able to do so,” the tweet said.

It was unclear what was delaying the deal between the powers — the United States, Britain, Russia, China, France and Germany — and Iran.

The tweet runs counter to public statements from Iranian President Hassan Rouhani.

“During the talks in Vienna many gaps were narrowed and our positions with the other side got closer,” Rouhani told Iranian state television Monday. “I am certain that we will reach the final accord, if not today, then tomorrow.”

Other recent tweets from the Khamenei account accuse the U.S. of wanting to keep a war among Muslims alive and express the desire that the West Bank should “also be armed like Gaza.”

Not all the comments condemned the negotiations, however. A picture posted to the account earlier included a quote from a talk that Khamenei gave to Iranian students last year.

“If [the Iranian administration] achieves results, then so much the better,” the quote said in part. “But if not, this should mean that the country must stand on its own feet in order to solve the problem.”