By Samia Nakhoul, Laila Bassam and Suleiman Al-Khalidi

Beirut (Reuters) - Lebanon’s Hezbollah said the partition of Iraq and Syria was a possible outcome of sectarian fighting across the region and there was no prospect of any end to the war in Syria until after November's U.S. presidential election.

Sheikh Naim Qassem, deputy leader of the Iran-backed group, whose forces are fighting alongside President Bashar al-Assad against rebels supported by Western and regional powers, said Hezbollah, Iran and Russia would stand by Assad until the end.

In an interview with Reuters, he said recapturing Aleppo, Syria’s second major city where a decisive battle is unfolding, remained an objective but was not an immediate goal.

The U.S. and its allies say that by waging war against his own people, Assad can have no future in Syria, while Russia and Iran, wholly opposed to regime change, maintain he is the legitimate president, albeit of a state shrunk by rebel gains.

Both coalitions fear his sudden departure could destroy what is left of Syria after more than five years of civil war, bequeathing a shell state to the jihadis of Islamic State and Al Qaeda.

Qassem said both Syria and neighboring Iraq, where Islamic State has also seized territory, could split.

"On the battlefield and in view of regional and international interventions I don’t rule out that one of the ideas proposed is finding a state of partition in those two countries but will it succeed or not?

"So far the forces that want the unity of Iraq and Syria are able to prevent the idea of partition but we should remain worried about ... the possibility that some countries might push these two countries or one of them into partition."

Assad was the best protection against this, Qassem said.

"With President Assad the solution can be logical and rational in finding political parameters that can give the opposition its share and the regime its share and there could be coordination which allows for putting things back in order and reviving authority in Syria”, the white-turbaned sheikh said.

DIE-HARD COMMITMENT

The intervention of Russia’s air force since last September, after Iran, Hezbollah, and Iraqi Shi’ite militiamen had fought relentlessly to keep Assad in place, has confounded the designs of Washington and regional Sunni powers such as Saudi Arabia and Turkey, Qassem said, opening the way to a political solution.

"Iranian and Russian relations with Syria helped achieve steadfastness on the ground because both support Assad staying in power and back a political solution,” the Hezbollah number two told Reuters.

The Syria war grew out of Arab spring-inspired protests in 2011 calling for democratic change. Before Iran, Hezbollah and Russia came to Assad’s aid, his grip on power appeared to be failing. Their support was seen by diplomats and Middle East experts as key to Assad's survival.

Syria's civil war, now in its sixth year, has killed more than 250,000 people, displaced more than 6.6 million inside the country and forced another 4.8 million to flee, creating a huge influx into neighboring countries and Europe.

Qassem said the months-long push on rebel-held Aleppo by Assad's government forces was aimed less at recovering Syria’s major city than at separating the rebels from Idlib, their stronghold in the north-west, and choking their supply lines from Turkey.

Aleppo, with a population of more than 2 million people now, has been divided for years into rebel and government areas.

“The main objective of the Syrian state and allies was to cut the road between the city of Aleppo and Idlib. As for liberating Aleppo that's a different goal that may not be undertaken quickly..."

"Regaining Aleppo will remain one of the goals of the Syrian state and its allies but we're not tied to a timeframe", said the Hezbollah leader.

FIGHTING GLOBAL THREAT

The Lebanese group, a Shi'ite Islamist party with a powerful armed wing, describes its role as part of a struggle against the growing regional threat presented by Sunni Muslim jihadists, who it labels takfiris for their radical ideology, violent and uncompromising stance.

The conflict in Syria has further fueled an old regional rivalry between the Shi'ite Islamist government of Iran and the conservative Sunni Muslim kingdom of Saudi Arabia, one of the main sponsors of the insurgency against Assad.

Qassem said the United States, one of the power brokers in finding a solution to the crisis, was distracted by its November presidential elections and not ready to commit to any action until a new president takes over next year.

“The US administration is convinced that the period ahead of the presidential elections is a wasted time, that it can await until the new president assumes power. Then, the prospects of a solution or of a prolongation of the crisis will be clear."

He said the sacrifices of Hezbollah, which has lost hundreds of fighters in Syria, were worthy, otherwise the ultra-hardline jihadists of Islamic State would have taken control in Syria and expanded into Lebanon.

"We have prevented the expansion of the crisis into Lebanon and this is a major achievement, we prevented the takfiris from disrupting the resistance and laid the basis for the steadfastness of Syria. These great achievements deserve every sacrifice," he said.

He said Islamic State, which is being targeted by coalition air strikes, will increase its attacks in Europe and beyond, adding that the group has an expansionist strategy and will use any means to achieve its goals.

"European pains are big and will increase more and more," Qassem said, adding that Islamic State "will not leave an opportunity in all the countries of the world without exception to attack when it can and when is able to."

(Editing by Philippa Fletcher)