LONDON (AFP) – 8 Sep. 2016- Syria’s opposition on Wednesday made a fresh call for a transition to democracy without Bashar al-Assad, as Russia and the United States agreed to hold a new round of talks aimed at ending the war.

The proposal by the opposition during one-day talks in London came as the world’s chemical weapons watchdog on Wednesday said it was “disturbed” by the alleged use of toxic chemicals in the battleground city of Aleppo.

Russian Foreign Minister Sergei Lavrov and his US counterpart John Kerry, whose countries back opposing sides in the Syrian civil war, decided to meet on Thursday and Friday in Geneva to try to hammer out a deal, Moscow said.

The two top diplomats agreed to a “personal meeting” to work out an accord  and pushing forward the peace process in Syria, a foreign ministry statement said.

The agreement came after US President Barack Obama and his Russian counterpart Vladimir Putin failed on Monday to reach a deal on the sidelines of a G20 meeting in China to stem the violence.

Russia and the US are seeking to revive a ceasefire on the ground and coordinate strikes against the Islamic State group and other jihadists.

But with prospects for peace still more elusive than ever, the broad-based opposition High Negotiations Committee (HNC) proposed — during talks with its foreign allies in London — a six-month negotiating phase with the regime.

The opposition hopes the talks would result in an 18-month transition that would see Syria governed by a transitional body made up of opposition figures, current government representatives and members of civil society, according to a 25-page blueprint.

Its proposal came even as armed rebels faced enormous pressure on the ground, particularly around Aleppo where regime forces backed by the Russian air force have completely encircled opposition-held neighbourhoods.

The group’s plans are largely in line with existing international proposals for a post-war Syria, although unlike a 2015 agreement hashed out in Vienna, they are clear about Assad’s future.

– ‘No role’ for Assad –

A transition, HNC says, “shall require the departure of Bashar al-Assad and his clique who committed heinous crimes against the Syrian people.”

The group’s leader Riad Hijab, who spoke in London ahead of the talks, insisted that regime leaders who killed Syrians “cannot have a role in the future of Syria and in this transitional phase at all”.

Hijab, a former Syrian prime minister who defected to the opposition in 2012, blamed the failure of previous rounds of peace talks on “a refusal to talk about the political transition”.

The proposals, and the talks hosted by British Foreign Secretary Boris Johnson, came as the conflict raged relentlessly and on multiple fronts, particularly around Aleppo.

On Wednesday the world’s chemical weapons watchdog condemned the alleged use of toxic substances in Aleppo, once Syria’s economic capital, after dozens of people had to be treated for breathing problems there.

“Such allegations are taken very seriously. The use of chemical weapons by anyone, anywhere and under any circumstances is unacceptable,” Ahmet Uzumcu, head of the Hague-based Organisation for the Prohibition of Chemical Weapons, said in a statement.

More than 70 people were left choking on Tuesday after regime helicopters dropped barrel bombs on a rebel-held district of the war-ravaged city, a monitoring group said.

– ‘Barbaric military tactics’ –

In an article in Wednesday’s edition of The Times, Johnson urged Russia to cease support for the Syrian president.

The British diplomat accused Assad of “barbaric military tactics” in the ongoing conflict and criticised Russia’s “seemingly indefensible conduct” in backing him.

“The entire international community is committed, at least in principle, to getting rid of the Syrian dictator. Even the Russians have accepted that there must be political transition,” he wrote.

“But then the Russians are also employing their military muscle to prevent him from losing and to keep him in power.”

The talks in London were also due to involve foreign ministers from Turkey, Jordan, Qatar, United Arab Emirates, Italy and France, as well as representatives of Germany and the EU.

Kerry was due to take part via video-link.

The Syrian war, which began as a pro-democracy revolt but later morphed into a multi-front conflict after the regime unleashed a crackdown, has killed more than 290,000 people and forced more than half the population to flee their homes.