NSW Premier Gladys Berejiklian has ruled out pill testing as an option for New South Wales festivals, despite assembling an expert panel to make recommendations on how to improve the safety of music festivals.

This follows the deaths of two people due to suspected drug overdoses as Defqon 1 festival in Sydney over the weekend. 

Premier Berejiklian also backtracked on her earlier promise to shut down Defqon 1, instead saying the festival needs to improve its safety requirements. 

The panel is expected to provide its recommendations within four weeks.