ENNISKILLEN, Northern Ireland (AP) -- World leaders including the U.S. and Russia declared Tuesday they are united in wanting a negotiated and peaceful end to the Syrian civil war that will produce a government "under a top leadership that inspires public confidence."
The declaration at the end of the two-day Group of Eight summit sought to narrow the ground between Syria government backer Russia and Western leaders on starting peace talks in Geneva that could end with the ouster of Bashar Assad from power.
It stopped short of demanding Assad's removal as leader, nor did it advance the possibility of sending U.S., British or French weapons to rebels, an option being kept open by all three G-8 members. Russia refused to back any declaration that made such Assad's removal from power an explicit goal.
And reflecting the profound divisions that remain after two days of talks, the British host, Prime Minister David Cameron, declared in response to reporters' questions that it was "unthinkable" that Assad could play any role in Syria's post-talks government.
"He has blood on his hands. He has used chemical weapons," Cameron said, a position rejected as unproven by the Russians.
Russian President Vladimir Putin said arms supplies to the Syrian opposition would destabilize the situation even further.
"Any decisions to provide the opposition with weapons based on unconfirmed accusations against Damascus of using chemical weapons will only further destabilize the situation," Putin said at a news conference.
Significantly, the G-8 declaration said participants in any peace talks must agree to expel al-Qaida-linked fighters from Syria. That measure reflects growing Western unease at the human rights abuses being committed in rebel-held areas, including civilian executions on Muslim extremist grounds.
The declaration condemned human rights abuses committed by government forces and rebels alike, and called on both sides to permit access by U.N.-led chemical weapons experts trying to investigate the contentious claims of chemical weapons use.
In its only concrete commitment, the plan commits a further $1.5 billion in aid for Syrian refugees.
Earlier, G-8 leaders announced new goals to combat tax avoidance by multinational companies. In a joint statement they said tax authorities should share information "to fight the scourge of tax evasion" and make it harder for companies to "shift their profits across borders to avoid taxes."
But the key word in that document, often repeated, may well be "should" — because the partnership made no formal agreement on any specific reforms. The agreed aspirations will be developed at this year's G-20 summit in September.
Still, Britain heralded the agreement as a good first step toward creating a new environment of corporate transparency. A key principle in the plan would require multinationals to declare how much tax they pay in each country.
The G-8 is made up of Britain, the U.S., Germany, Russia, France, Italy, Canada and Japan. The group's tax initiative reflects widespread anger over the ability of foreign companies to funnel profits to tax-friendly countries.
Cameron began Tuesday with what his spokesman called a "brisk" swim in the chilly waters of scenic Lough Erne, the lake beside the Northern Ireland golf resort hosting the summit, before heading in to lead the summit's second and final day.
British lawmakers have sharply criticized Google, Starbucks and other U.S. multinationals operating in Britain for exploiting tax rules by registering their profits in neighboring countries such as Ireland — which charges half the rate of corporate tax — or paying no tax at all by employing offshore shell companies.
Many of the world's leading companies, ranging from Apple to the management company of U2, employ complex corporate structures involving multiple subsidiaries in several countries to minimize the tax bills in their home nation. One such maneuver, called the "double Irish with a Dutch sandwich," allows foreign companies to send profits through one Irish company, then to a Dutch company and finally to a second nominally Irish company that is headquartered in a usually British tax haven.
Washington said it was committed to reforming the global accounting rules and collecting more of U.S. companies' profits banked outside American shores.
"The goal of cracking down on tax avoidance, bringing greater transparency to it, this is something we've pursued in the United States, and we agree with Prime Minister Cameron that we can work together multilaterally to promote approaches that achieve those objectives," said Ben Rhodes, President Barack Obama's deputy national security adviser.
Campaigners for greater tax transparency appealed to the G-8 to ensure that reforms benefited the poorest countries of Africa, South America and Asia as well as the rich West. Anti-poverty campaigners have stressed that shell companies are a key method of spiriting away funds from a country.
Cameron says Britain will lead by example by creating a registry of who really owns companies, and will consider making it public — an idea viewed skeptically by many other countries fearful of scaring companies out of their jurisdictions.
"G-8 leaders must decide whether they want to shape the transparency revolution or resist the tide of history," said Adrian Lovett, Europe executive director at development campaign group One.
However, Britain itself stands accused of being one of the world's main links in the tax-avoidance chain. Several of Britain's own island territories — including Jersey, Guernsey and the British Virgin Islands — serve as shelters and funnel billions each week through the City of London.
"Of course, Britain's got to put its own house in order," said Britain's treasury chief, Chancellor of the Exchequer George Osborne, who addressed the G-8 meeting on corporate tax reform along with International Monetary Fund managing director Christine Lagarde.
Before the summit, Britain announced a provisional agreement with the finance chiefs of nine of its offshore dependencies and territories to improve their sharing of information on individuals and companies banking cash there.
Also Tuesday, Cameron won commitment from all eight nations to stop paying ransoms to kidnappers in hopes of deterring the practice following January's bloody capture by al-Qaeda-linked militants of an Algerian gas facility. Ten Japanese, five Britons, three Americans and a French national were among the 40 civilians killed as Algerian forces retook the facility.
Hostage-taking of foreign workers for cash payments is on the rise across much of West Africa, particularly Nigeria with its own oil industry dominated by Western companies and foreign managers.
Cameron invited the leaders of Libya and the African Union to join the talks over lunch to discuss the issue.
The summit was concluding with rapid-fire statements by each departing leader. Obama was scheduled to continue his European trip Tuesday night in Germany.
Vladimir Isachenkov contributed to this report.