Edinburgh International Festival director Jonathan Mills has called for a "measured and mature" response to the threat of funding cuts.
Mr Mills said the festival provided performances on a scale which the Edinburgh Fringe could never match.
He said there would be "inevitable challenges" but he was focused on how to "survive and flourish".
The 64th International Festival opens later with a performance of US composer John Adams's nativity oratorio El Nino.
Unlike the Edinburgh Fringe, the International Festival is "curated" and artists appear only at the invitation of the director.
It presents a rich programme of classical music, theatre, opera and dance in six major theatres and concert halls and a number of smaller venues.
However, the festival is heavily subsidised, with more than half of its £9m turnover from public bodies.
Edinburgh City Council has already announced a 3.5% cut in funding and Creative Scotland's contribution has been frozen.
The full extent of government cuts is still unclear and the actual impact on the festival could be far greater.
Mr Mills warned against "talking ourselves into thinking things are more extreme than they may be in reality".
He said: "It is important not to overstate, in the absence of hard evidence, how extreme the cuts will be.
"We need to have a measured and mature response to the inevitable challenges.
"Let's focus on how we are going to survive and flourish."
Mr Mills also defended the International Festival after a public clash with the boss of a major Fringe venue.
Charlie Woods, co-founder of Underbelly, said the Fringe, which receives very little public funding, could "pick up the baton" if cuts had a major impact on the International Festival.
Mr Mills said the Fringe could never replicate the scale of the International Festival's productions, which often have 100 performers and a full orchestra.
He said the size of the Fringe was impressive - more than 2,400 shows - but they were all quite small-scale.
"The International Festival pays for itself in spades with the number of people who come to Edinburgh and the attention it brings to the city.
"It comes down to whether you want a very broad and diverse cultural offering or whether you want a narrow entertainment."
Mr Mills added that the Fringe's purely commercial model - open to anyone who wants to stage a show - also had "enormous fragility" and was at the whim of the market.