Britain and France on Wednesday renewed their call for Syrian President Bashar al-Assad to go, after a suspected chemical weapons attack by Damascus killed scores of people in a rebel-held area.
Foreign ministers Boris Johnson of Britain and Jean-Marc Ayrault of France spoke during an international conference on Syria, which the European Union convened in Brussels in a bid to shore up stalled peace talks between Assad and his rivals.
"This is a barbaric regime that has made it impossible for us to imagine them continuing to be an authority over the people of Syria after this conflict is over," Johnson said.
Ayrault said the attack was a test for the administration of U.S. President Donald Trump.
The future of Assad, who is backed militarily and politically by Russia and Iran, has been the main point of contention blocking progress in talks. The war has raged for more than six years, killing 320,000 people, displacing millions and leaving civilians facing dire humanitarian conditions.
"The need for humanitarian aid and the protection of Syrian civilians has never been greater. The humanitarian appeal for a single crisis has never been higher," United Nations' Secretary General Antonio Guterres said.
The U.N. has called for $8 billion this year to deal with the crisis and the Brussels gathering was due to come up with fresh pledges of aid.