DUBAI - Iranian Supreme Leader Ayatollah Ali Khamenei said on Saturday he supported moderate President Hassan Rouhani's diplomatic initiative at the UN General Assembly last week but that some of what occurred there was "not proper."

In his first comments since Rouhani's visit to the US, which included a telephone conversation with US President Barack Obama, Khamenei also emphasized that he does not trust the United States as a negotiating partner.

The phone call between Rouhani and Obama, the highest-level contact between the two deeply estranged countries since 1979, capped off a week of overtures by Rouhani and his foreign minister Mohammad Javad Zarif to the West.

The landslide election in June of Rouhani, a centrist cleric, has raised hopes of a negotiated settlement to Tehran's long-running dispute with the West over its nuclear program - though it is Khamenei who will make the final decision on the contours of any deal.

"We support the government's diplomatic movements and place importance on diplomatic efforts, and support what was in this last trip," Iran's ISNA news agency quoted Khamenei as saying in a speech. "Of course, in our opinion some of what occurred in the New York trip was not proper."

He did not elaborate on that point, but added: "While we are optimistic about our government's diplomatic staff, we are pessimistic about the Americans. The US government is not trustworthy, is self-important, and breaks its promises."

During Rouhani's recent speech to the UN in New York, he called for "time-bound" talks on its nuclear program with the West while harshly criticizing US interference in the Middle East.

He also harshly criticized Western powers economic-sanctions that have been imposed on Iran. "Sanctions, beyond any and all rhetoric, create belligerence, warmongering and human suffering," he said.

Despite Prime Minister Binyamin Netanyahu's repeated warnings of what he says are Rouhani's true intentions in opening the door for dialogue with the West, the Iranian president has asserted that "My country has been a harbinger of just peace and comprehensive security."

Netanyahu called Rouhani's speech at the assembly a "cynical speech full of hypocrisy.

In his own speech to the UN, Netanyahu outlined the length to which he feels the Iranian nuclear program poses a threat to Israel and the West. However, Netanyahu added that Israel was prepared to "stand alone" if necessary in the fight against Iran.

Michael Wilner contributed to this report.

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