Merkel says Germany can't 'look away' if Assad uses chemical weapons in Idlib offensive

German Chancellor Angela Merkel said on Wednesday that Germany could not simply "look away" if Syrian regime head Bashar al-Assad uses chemical weapons again in the country's devastating conflict.

"The German position cannot be to say 'no' from the outset, no matter what happens anywhere in the world," Ms Merkel said in a speech to parliament on Wednesday.

Germany's Foreign Minister Heiko Maas said diplomacy was the priority to prevent the use of chemical weapons in Syria, but defence minister Ursula von der Leyen said a "credible deterrent" was also needed.

"To simply say we can look away when chemical weapons are used somewhere and international conventions are broken cannot be the answer," Merkel said. 

If Germany were to respond to the use of chemical weapons it would be based on the constitution and within "the framework of our parliamentary commitments", she added.

On Wednesday, UN investigators said they had documented three further uses of banned chemical weapons by Syrian regime forces that constituted war crimes.

They urged major powers to avert a "massacre" as Assad's forces prepare for an expected assault on Idlib, the last rebel stronghold in the country.

Earlier on Wednesday, the US warned Assad against using any chemical weapons ahead of the anticipated regime offensive on Idlib.

US air and missile strikes have previously targeted the Assad regime twice after using chemical weapons in attacks.

US officials have in recent days said additional action would follow if Assad were to use the banned weapons in Idlib province. 

Germany did not participate in the military strikes by US, French and British forces on Syria in April after a chemical weapons attack on Douma killed as many as 60 people.

The Syrian Archive have documented 212 chemical attacks in Syria since the start of the war in 2011.

Independent bodies have said the Syrian regime is almost certainly responsible for the vast majority of these attacks, including the use of sarin on the Khan Sheikoun in Idlib, which left around 100 dead.

Around 500,000 people have died and millions made homeless in seven years of fighting in Syria, which was sparked when regime forces brutally put down peaceful protests in 2011.