Iran successfully tested the missile recently, which burns a combination of solid and liquid fuels and has a range of 2,000 kilometers.
"This is a whole new missile," Uzi Rubin, former director of Israel's Ballistic Missile Defense Organization, told Jane's military intelligence website.
"Unlike other Iranian missiles, Sejjil bears no resemblance to any North Korean, Russian, Chinese or Pakistani (missile technology). It demonstrates a significant leap in Iran's missile capabilities," he added.
"Regardless of the success of the test, this missile places Iran in the realm of multiple-stage missiles, which means that they are on the way to having intercontinental ballistic missile capabilities," Rubin noted.
Iran has said that its missile capability is of a defensive nature.
Israel and its close ally the United States accuse Iran of seeking a nuclear weapon, while they have never presented any corroborative document to substantiate their allegations. Both Washington and Tel Aviv possess advanced weapons of mass destruction, including nuclear warheads.
Iran vehemently denies the charges, insisting that its nuclear program is for peaceful purposes only. Tehran stresses that the country has always pursued a civilian path to provide power to the growing number of Iranian population, whose fossil fuel would eventually run dry.
Speculation that Israel may bomb Iran rose after a military exercise by the Zionist regime earlier this year. In early June, Israel conducted a military maneuver over the eastern Mediterranean and Greece in preparation, according to Pentagon officials, for an aerial bombardment of Iranian nuclear facilities.
Over 100 Israeli F-16s and F-15s partook in the exercise, which spanned some 900 miles, roughly the distance between their airfields and a nuclear enrichment facility in the central Iranian city of Natanz.
The United States has also always stressed that military action is among its main options on the table.
In response, Iran has warned it could close the strategic Strait of Hormoz if it became the target of a military attack over its nuclear program.
Strait of Hormoz, the entrance to the strategic Persian Gulf waterway, is a major oil shipping route.
Intensified threats by Tel Aviv and Washington of military action against Iran are in direct opposition to a recent report by 16 US intelligence bodies which endorsed the civilian nature of Iran's nuclear plans and activities.
Following the US National Intelligence Estimate (NIE) and similar reports by the IAEA head - one in November and the other one in February - which praised Iran's truthfulness about key aspects of its past nuclear activities and announced settlement of outstanding issues with Tehran, any effort to impose further sanctions or launch military attack on Iran seems to be completely irrational.
The February report by the UN nuclear watchdog, the International Atomic Energy Agency, praised Iran's cooperation in clearing up all of the past questions over its nuclear program, vindicating Iran's nuclear program and leaving no justification for any new UN sanctions.
The UN nuclear watchdog has also carried out at least 14 surprise inspections of Iran's nuclear sites so far, but found nothing to support West's allegations.
Following the said reports by the US and international bodies, many world states have called the UN Security Council pressure against Tehran unjustified, demanding that Iran's case must be normalized and returned from the UNSC to the IAEA.
Meantime, a recent study by the Institute for Science and International Security (ISIS), a prestigious American think tank, found that a military strike on Iran's nuclear facilities "is unlikely" to delay the country's program.