Sarin traces found in Syria chemical weapons attack

(CNN) -- British military scientists found traces of sarin gas in soil and clothing taken from a patient treated near the site of an alleged chemical weapons attack outside Syria's capital, the prime minister's office said Thursday.

Scientists at the Porton Down military laboratory concluded the samples were unlikely to have been faked, and Britain is sharing its findings with the United Nations, the office said.

The revelation is the most specific statement by British officials regarding the chemical they believe was used in the August 21 attack on a rebel stronghold near Damascus, though the office didn't explicitly say who was responsible. U.S. officials have, blaming Syrian government forces for an attack they say left more than 1,400 people dead, many of them children.

The British statement is not the first allegation that sarin gas -- an extremely volatile nerve agent that can kill -- has been used in Syria's gruesome, two-year civil war.

In June, France's foreign minister said samples in his nation's possession showed sarin gas had been used several times in Syria. The United States has made such assertions on multiple occasions, including in April when Defense Secretary Chuck Hagel alleged there's evidence sarin had been used lethally on a small scale. More recently, Secretary of State John Kerry said Sunday that blood and hair samples from near the August 21 eastern Damascus attack site "tested positive for signatures of sarin" gas.

Echoing rebel forces, Washington has insisted that Syrian President Bashar al-Assad's forces are behind such chemical weapon attacks, claiming only they have access to them and can deploy them on a large scale. Yet Syria has been equally adamant that it has done no such thing, instead accusing "terrorists" -- its blanket term for opposition fighters -- of deploying chemical weapons.

Who is to blame, and what the world should do about it, looms large over Thursday and Friday's G-20 gathering of world leaders in St. Petersburg, Russia.

The summit's focus is officially on economic matters, though the deep divisions among its participants on this pressing issue are hard to ignore: the U.S. and French leaders are calling for a military strike against Syria's government, while Russian leaders are standing by their longtime ally and questioning claims al-Assad's government is responsible for gassing its own people.

How these talks influence the debate, if at all, is itself in question.

When asked Thursday while walking alone to dinner if any progress had been made on Syria, U.S. President Barack Obama said, "No, we talked about the economy."

Debate ongoing in Washington, elsewhere on what to do

Kerry said this week, in Washington, that "at least 10 countries have pledged to participate" in a military intervention that Obama and French President Francois Hollande have urged. Yet that figure, could well change.

Britain, normally a dependable U.S. ally in military affairs, has voted against joining any military action. And officials in France -- where polls show one in three people favor strikes -- have said they will wait until the United States decides on a course of action.

That won't come until after Congress weighs in, likely next week, on a measure authorizing strikes focused on degrading Syria's ability to use chemical weapons. While congressional leaders have backed Obama's call for action, most legislators are officially undecided so much that what happens is still anyone's guess.

"It weighs on me," said Sen. Dianne Feinstein, D-California, who added "it is conclusive" chemical weapons were used. "... There is no question that what (public reaction) is coming in is overwhelmingly negative."

Yet the president -- arguing that the world cannot afford a country to use such weapons against its own people without responding -- hasn't promised he'll abide by the vote in Congress. And Pentagon spokesman George Little said the Syrian government "should not take solace from the deliberative process that we are undertaking right now."

"We have time to adjust, if necessary, given conditions on the ground, given what the Syrian regime may or may not do in terms of movements of equipment and so forth," Little told reporters Thursday.

Iranian leader: U.S. will 'definitely suffer' if it strikes

Whatever the United States decides, some world leaders are stumping against military action.

Speaking from the G-20 summit, European Council President Herman Van Rompuy said that while the international community "cannot remain idle" in the face of Syria's apparent chemical weapons use, "there is no military solution to the Syrian conflict."

"Only a political solution can end the terrible bloodshed, grave violations of human rights and the far-reaching destruction of Syria" he said. "Too many lives have already been lost and too many people have suffered for too long and lost too much."

Pope Francis also spoke out, sending a letter Thursday to Russian President Vladimir Putin in his role as host of the G-20 summit urging a "peaceful solution through dialogue" and calling military intervention a "futile pursuit."

Some of the Syrian government's biggest allies were not so measured in their responses.

In its first official reaction to a potential U.S.-led strike, Hezbollah -- a group popular in parts of the Arab world yet labeled a terrorist organization by the United States -- called such military action "a form of direct and organized terrorism."

"These threats fail to conceal the true objectives of this strike," Hezbollah alleged in a statement read by parliamentarian Hassan Fadlallah, as reported Lebanon's official National News Agency, "aimed at mobilizing Israeli (strength) in the region in an attempt to impose the Western colonial grip."

In remarks carried by Iran's state-run Press TV, Ayatollah Ali Khamenei said the United States has no right to make "humanitarian claims (given) their track record" in Iraq, Afghanistan and at the military prison in Guantanamo Bay.

If Washington carries out strikes, it will pay a steep price, Iran's leader added.

"We believe that the Americans are committing a folly and mistake in Syria and will accordingly take the blow and definitely suffer," he said.

Russia, U.S. stake out divergent positions

Wherever they stand in the debate, few dispute the fact Syria has suffered greatly since 2011.

The United Nations estimates that more than 100,000 people have been killed since that time, when government forces cracked down on peaceful demonstrators. The ensuing chaos spiraled into a civil war, with scores of deaths reported every day -- including at least 42 more Thursday, according to the opposition Local Coordination Committees of Syria.

More than 2 million Syrians have fled their country, the U.N. refugee agency says, and more than 4 million are internally displaced.

Leaders in the international community have intermittently condemned the violence, urged restraint and called for a political solution. But any such attempts at peace have failed, as have efforts to push actions punishing al-Assad's government through the U.N. Security Council -- several of which have been blocked by Russia, which has veto power.

One of those still trying is Lakhdar Brahimi the joint U.N.-Arab League envoy to Syria whose plan for a cease-fire fell apart. He's among those at the G-20 summit, hoping to meet with Obama and Putin to push for new peace talks for Syria, spokeswoman Khawla Mattar said.

A sweeping international consensus seems unlikely as long as Russia -- which will host Syrian Foreign Minister Walid Muallem in Moscow on Monday, according to Syria's official SANA news agency -- and the United States maintain their firm positions.

Putin told Russia's state Channel 1 television and The Associated Press this week that, while he "doesn't exclude' backing military action in Syria if given undeniable proof Syria's government was behind the August attack, he finds it "absurd" al-Assad's forces would have done so.

As to Obama, he told reporters before heading to Russia that "the international community's credibility is on the line."

Arguing it was imperative to strike Syria, the president said, "The moral thing to do is not to stand by and do nothing."