ENNISKILLEN, UK - G8 leaders on Tuesday threw their weight behind calls for a peace conference on Syria to be held in Geneva “as soon as possible”, after a summit dominated by the country’s civil war.

At the end of two days of talks in Northern Ireland, the leaders also called for agreement on a transitional government in Syria “with full executive powers, formed by mutual consent”.

British Prime Minister David Cameron, the summit host, said it was “unthinkable” that President Bashar al-Assad could play a role in a transitional administration, but the G8 communique pointedly made no reference to him, in an apparent concession to Syria’s ally Russia.

After talks which at times pitted Russian President Vladimir Putin against his fellow G8 leaders, the final communique said the Syrian military and security services “must be preserved and restored” in a future set-up.

The leaders did not suggest a date for the proposed Syria talks, which were supposed to take place this month but have already been delayed.

And they agreed to stamp out the payment of ransoms for hostages kidnapped by “terrorists”, and called on companies to follow their lead in refusing to pay for the release of their employees.

The world’s most industrialised nations also called on companies to follow their lead in refusing to pay for the release of abducted employees.

British Prime Minister David Cameron, the summit host, had been keen to push the deal because funds raised by ransom payments are a substantial source of funding for terror groups, especially those in north Africa.

Al-Qaeda-linked groups around the world have made $70 million from mainly Western hostages over the last two years, British officials said.

The G8 leaders said in their final communique they “unequivocally reject the payment of ransoms to terrorists”.

They added: “The payment of ransoms to terrorist groups is one of the sources of income which supports their recruitment efforts, strengthens their operational capability to organise and carry out terrorist attacks, and incentivises future incidents of kidnapping for ransom.”

Britain was particularly focused on the subject following a hostage crisis at a gas plant in Algeria in January in which 37 foreign hostages were killed, among them six Britons.

Five of the G8 nations had been “shifting” on the issue while three did not pay ransoms as a matter of principle, British officials said.

Cameron’s spokesman said the agreement among his G8 colleagues was “very strong”. “That the G8 sending a very clear, unambiguous message on this is important,” the spokesman told reporters.

It would target “proscribed organisations”. But the summit was dominated by the conflict in Syria, which has cost more than 90,000 lives since it broke out in March 2011.

The G8 nations pledged almost $1.5 billion (1.1 billion euros) in humanitarian aid for refugees inside and outside Syria, including $300 million from the United States and 200 million euros from Germany. After Washington said it would arm the Syrian rebels and the EU mulled the issue, the G8 said it was deeply concerned at the growing extremism and “terrorism” in Syria.

The world leaders called on the regime and the opposition to “commit to destroying and expelling from Syria all organisations and individuals affiliated to Al-Qaeda, and any other non-state actors linked to terrorism”.

Putin’s sharp differences with US President Barack Obama over Syria were laid bare in icy face-to-face talks on Monday.

“If we conclude such contracts, then we will deliver on such contracts,” he told reporters after a G8 summit in Northern Ireland.

“Europe wants to send arms to these people? And what happens then to these arms? Who will control in whose hands and where they will end up? Maybe in Europe?”

He also rejected US and European assertions that Syria’s regime had used chemical weapons. “We do not have facts pointing to the use of such weapons by the Syrian government,” Putin said.

“I assure you that, by far, not all G8 members believe that (chemical arms) were used by the Syrian army. Some agree with our opinion that there is no such data.” Despite coming under pressure from other G8 leaders to back away from Moscow’s support for Syria’s regime, Putin denied that he felt isolated at the summit.

“Of course, it is not so,” he said. “It was a joint discussion. Not a single time did it happen that Russia was left alone in defending its approaches to the solution of the Syrian problem.”

Gathered on the picturesque banks of Lough Erne, the world’s leading industrialised nations also struck a deal to crack down on tax evasion and share more cross-border financial information.

They vowed concrete steps to target not only illegal tax evasion but also tax avoidance by multinational companies that costs taxpayers billions in lost revenues. Aside from Syria, Cameron heralded a commitment to fight the “scourge” of tax evasion and to promote corporate transparency.

The final declaration also called for greater transparency on corporate ownership. But activists said the deal came up short. The summit also saw the launch of formal negotiations on a vast trade pact between the United States and the European Union.

It was guarded by 8,000 police officers in the biggest security operation ever mounted in Northern Ireland’s troubled history, but protesters were thin on the ground. President Barack Obama expressed skepticism Monday that setting up a no-fly zone in Syria or other major US military action could save lives or tip the balance against Assad’s regime.

Speaking to PBS television, Obama said critics urging bold intervention failed to understand there was no simple solution and “if you set up a no-fly zone, that you may not be actually solving the problem.”