The West 'must get tougher' with Assad, urges Syria opposition

Nasr Hariri said on Monday that Syrian civilians will continue to be killed until the West forces Assad and his allies to agree to peace.

"I would like to ask all those countries that promised they would support the Syrian people and their aspirations for democracy and peace: why didn't they fulfil their promises?" Hariri told Reuters in London.

Trump and EU leaders such as German Chancellor Angela Merkel, French President Emmanuel Macron and British Prime Minister Theresa May need to get tougher with Assad, added Hariri.

Since the start of Syria's war in 2011, numerous diplomatic attempts to halt the conflict have stumbled, mainly over the future of Assad.

The past two years have seen a number of victories by the Syrian army who have depended heavily on Russian air force and Iranian ground backing in order to regain lost territory from rebel forces.

In the past two months a Russian air offensive has helped capture nearly 100 towns and villages in the nearby Hama province and breached Idlib for the first time since mid-2015.

As the balance tips in favour of the Assad regime and his allies, most Western countries have quietly softened their positions on Assad needing to leave power as any part of peace deal.

"It is time for Trump, Merkel and May to increase pressure and bring the international community together to get a genuine and just political situation in Syria," said Hariri.

On Tuesday, the Syrian opposition announced plans to attend the UN peace talks in Vienna, previously held in Geneva. 

Earlier in the month, Russia's UN ambassador said he hoped the UN-led talks on Syria would "reinvigorate" the peace process ahead of the Russian-brokered talks planned this month in the Black sea resort of Sochi.

Vassily Nebenzia said that a round of Geneva talks "will be more fruitful, and that it will contribute to Sochi, and then Sochi in reciprocity will contribute to future Genevas."

Staffan de Mistura, the UN Syria envoy, said that Russia's plan to convene the congress is dependent on its ability to support the UN-led Geneva talks taking place.

He also needs Russia's support to keep Assad's regime involved in UN talks, which failed to make progress in December with De Mistura laying blame on Damascus for the "golden opportunity missed".

Hariri said it was very unlikely that the Syrian opposition would attend Sochi, but that no invitation had been received so far.

"We have not been invited yet," he said. "The general mood is not to go to Sochi. My personal view is that in its current shape, it is unacceptable to attend Sochi."

Late last month, a statement released by nearly 40 rebel groups, including some of the military factions that took part in the earlier rounds of the peace talks, said there was no real pressure being placed on the Syrian government by Moscow to reach a political settlement.