Federal Labor supports the US military strike against a Syrian airfield, describing it as appropriate and proportionate response to the deadly gas attack against civilians.
"We support the US sending a strong signal that these gas attacks should have never occurred - and they should never occur again," Bill Shorten said in a joint statement on Friday, with his foreign affairs and defence spokespeople Penny Wong and Richard Marles.
"The illegal and abhorrent use of chemical weapons by the Assad regime against its own people demanded a strong response."
The opposition renewed calls for the United Nations to take strong and appropriate action.
It also urged nations with influence on the Assad regime - namely Russia and Iran - to prevent it from conducting further crimes.
Mr Marles said the opposition was seeking a briefing on the strikes.
