TEHERAN (AFP) - Iran's supreme leader Ayatollah Ali Khamenei said on Saturday that a landmark nuclear deal with world powers "won't change" the country's stance toward the "arrogant" United States.

The remarks were greeted by chants of "Death to America" at a ceremony in Teheran marking the end of the Muslim fasting month of Ramadan, which was broadcast live on state television.

Khamenei also said Tuesday's nuclear agreement would not alter Iran's support for the governments of Syria and Iraq nor its backing of "oppressed people" in Yemen and Bahrain, and the Palestinians.

The supreme leader's comments reflected his longstanding position that Iran's engagement with the six powers was solely to reach a nuclear deal that was in its national interest.

He stressed that the deal with Britain, China, France, Russia and the United States plus Germany was not yet law and would have to be carefully scrutinised.

"They really took pains and worked hard," Khamenei said of Iran's negotiating team.

"The text that has been prepared, whether it is approved or not, they have done their part and they should have their reward," he added.

As Iran's supreme leader, Khamenei has the final word on all policy matters, foreign and domestic, including on the nuclear deal.

In numerous speeches before this week's accord, he appeared ambiguous about the talks, consistently talking down the chances of success but at the same time praising Iran's negotiators as trustworthy and brave.

Iran has always denied seeking an atomic weapon, insisting its nuclear programme is for peaceful energy and medical purposes only.