A senior Iranian official said on Tuesday he did not believe an Israeli military strike on Iran was imminent despite fresh Israeli media speculation the Jewish state might be considering one.

Israel has long refused to rule out a military response to Iran's nuclear program, which it believes aims at producing an atomic weapon. Tehran says the program is simply intended to generate nuclear power.

Israel attacked a suspected Syrian nuclear site in 2007 and, in 1981, destroyed a nuclear reactor in Iraq before it was set to start operating.

Tension has risen since last week, when the U.N. nuclear watchdog reported Tehran appeared to have worked on designing a bomb and may still be conducting secret research to that end.

Asked if he was concerned about a possible Israeli strike, Mohammad Javad Larijani, a foreign affairs adviser to Supreme Leader Ali Khamenei, said: If you mean that I think (a) military attack on Iran is imminent, definitely no.

If you mean that we should be on guard against any ... possible military attack on our land, yes, he told Reuters in an interview.

Iran learned that ... the hard way after being invaded by Saddam Hussein's Iraq in 1980, Larijani said, adding it was the duty of Iranians to be ready.

But if you are asking me ... if any military action against Iran is imminent from ... any side, I don't anticipate that, he said.

Larijani, also head of Iran's High Council for Human Rights, is visiting New York before a planned vote by a U.N. General Assembly committee on a resolution condemning the human rights situation in Iran.

Speculation in Israel about an attack on Iran has been fuelled by Israel's recent test-launching of a long-range missile and comments by Prime Minister Benjamin Netanyahu that Tehran's nuclear program posed a direct and heavy threat.

But Defence Minister Ehud Barak last week played down the speculation, saying no decision had been made on embarking on a military operation.

Iranian officials have responded to the speculation mainly with defiance. Khamenei warned Israel and the United States last week that any attack would be met with strong slaps and iron fists.