Ayatollah Ali Khamenei, Iran's supreme leader, greets the crowd during a ceremony in Tehran on Monday. (Office of Ayatollah Ali Khamenei via EPA)

In remarks made Monday, Iran's supreme leader insisted that the nuclear deal reached with world powers last month did not necessarily signal a larger rapprochement with the United States.

Although most Iran watchers believe that the pact has the approval of Ayatollah Ali Khamenei, his public rhetoric about the implications of the deal has been far less enthusiastic than that of President Hassan Rouhani and Foreign Minister Mohammad Javad Zarif.

Addressing a gathering of the Islamic Radio and Television Union in Tehran, the country's highest authority appeared to dismiss any suggestion that the deal, which was negotiated with the permanent member states of the U.N. Security Council and Germany, would lead to an opening with Washington.

He also seemed to recognize that the agreement, forged in Vienna, was hardly a fait accompli and could still be rejected by politicians in Congress and, to a lesser extent, by hard-liners in Iran.

"They thought this deal — and it is not clear if it will be passed in Iran or in America — will open up Iran to their influence," Khamenei said, according to Reuters, presumably referring to the United States.

"We blocked this path and will definitely block it in the future. We won't allow American political, economic or cultural influence in Iran," he said.

A version of Khamenei's comments was uploaded on a Twitter account associated with him.

The language here is familiar; Iran's clerics have long invoked the specter of American imperialist meddling in their speeches. Another tweet also took a swipe at the "arrogance and colonialism" of Britain, whose diplomats have embarked on a global publicity campaign embracing the nuclear deal.

So what is the supreme leader playing at?

Some of Iran's entrenched hard-liners perceive any compromise with the United States as a threat to the Islamic republic and the stability of its regime. Haleh Esfandiari, a senior Iranian American academic, outlines the fine line that Khamenei is walking in a recent piece for the Wall Street Journal:

Ayatollah Khamenei has the last word — but he appears to be trying to suggest that he stands above the fray. He wants to retain the support of Iran’s hard-liners and the moderates within the ruling establishment. He is aware of widespread hope among the public for an agreement that would lift the international sanctions hindering Iran’s economy and end the country’s standoff with the West. So he allowed negotiations to go forward — while expressing his doubts directly or through surrogates.

It should be noted that Esfandiari, who was held in solitary confinement in Iran's notorious Evin prison for 105 days, is hardly an apologist for the regime. As she explains, a majority of ordinary Iranians want the deal to go through as it would bring much-needed sanctions relief to the country's hobbled economy. But Khamenei also wants to preserve his hard-liner bona fides.

So expect the mixed messaging to continue in the weeks ahead. Just before the Vienna agreement was announced in mid-July, Khamenei had made statements about "red lines," regarding concessions Iran would and would not make. By the terms of the current accord, Iranian negotiators seemed to have crossed most of them.

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