French flag flies over Harbour Bridge

The tricolour is flying high above the Sydney Harbour Bridge as NSW Premier Mike Baird offers condolences to the people of France.

Mr Baird said the flag was flying "proudly and defiantly" after an horrific suspected terrorist truck attack in the French city of Nice which has left at least 80 people dead.

"We stand with you. And our hearts grieve with yours," Mr Baird tweeted on Friday.