An influential Saudi prince has demanded a place at the negotiation table during talks with Iran on its nuclear program.

Prince Turki al-Faisal, a former Saudi intelligence chief, spoke with The Wall Street Journal on the sidelines of the World Policy Conference in Monaco on Sunday. The prince said Saudi Arabia is dismayed that the administration of U.S. President Barack Obama has been working behind Riyadh's back to hash out an interim plan to increase international oversight of Tehran's nuclear program.

Prince Turki said that while he hopes Iran is serious with regard to the deal, it needs to show its Gulf Arab neighbors that it is willing to make other steps forward. Iran, the prince said, should, for example, stop sending its troops and those of Shia allies such as the Lebanese organization Hezbollah to fight in neighboring countries, including Syria.

"Iran is coming at us with a broad smile. Let's hope they are serious about that. We would like to see Iran first of all get out of Syria," he said.

Prince Turki's comments to the Journal came a day after he spoke with Reuters on the sidelines of the same conference, decrying the U.S. and Britain for doing little to help opponents of Syrian President Bashar al-Assad, who have been fighting against the regime for nearly three years.

Rebel's battling against Assad's government forces have been at an impossible disadvantage, Turki told Reuters, because the U.S. and Britain have refused to help them.

The U.S. and Britain suspended non-lethal aid to northern Syria on Thursday after reports that Islamic Front — a union of six major rebel groups — had taken buildings belonging to the Free Syrian Army's (FSA) Syrian Military Council on the border with Turkey.

Turki criticized the decision, saying the two countries had left the moderate FSA to fend for itself.

"What's more damaging is that since the beginning of this conflict, since the FSA arose as a response to Assad's impunity, Britain and the U.S. did not come forward and provide the necessary aid to allow it to defend itself and the Syrian people from Assad's killing machine," Prince Turki said.

"You have a situation where one side is lopsided with weapons like the Assad regime is, with tanks and missiles — you name it, he is getting it — and the other side is screaming out to get defensive weapons against these lethal weapons that Assad has," Turki said. "Why should he stop the killing?"

"That to me is why the FSA is in not as prominent position as it should be today, because of the lack of international support for it. The fighting is going to continue and the killing is going to continue."

Saudi Arabia and Qatar are the primary backers of the main opposition Syrian National Coalition and the FSA, which they have aided with weapons, training, money and military intelligence in the fight against Assad's government. Iran has been one of Assad's biggest support in the ongoing conflict that has left more than 110,000 Syrians dead and forced more than 2 million to flee.

Western countries have so far held back from providing rebels with heavy weaponry such as anti-tank and missile launchers for fear the machinery could fall into the wrong hands.

"For me ... (to bring a) successful end to this conflict would be to bring an end to the Assad regime. It is because of the Assad regime that everything is happening," Prince Turki said.

Commanders from the Islamic Front are due to hold talks with U.S. officials in Turkey in the coming days, rebel and opposition sources said Saturday, reflecting the extent to which the Islamic Front alliance has eclipsed the FSA brigades.

A rebel fighter with the Islamic Front said he expected the talks to discuss whether the United States would help arm the front and assign to it responsibility for maintaining order in the rebel-held areas of northern Syria.

Al Jazeera and Reuters