The chief of one of the world’s biggest mining firms says protectionist trade barriers set up to weather the storm of the GFC are no longer necessary.

BHP Billiton Chief Executive Andrew Mackenzie says rolling back trade restrictions could massively boost world trade, injecting as much as $US3 trillion into the global economy.

Mr Mackenzie says there are more than 1,500 non-tariff restrictions imposed since the crisis hit, and now it the time to cut them.

Speaking to reporters for ABC international service the Australia Network, Mackenzie said millions of jobs would be created through more liberal trade.

He said he supports multilateral and bilateral trade agreements provided they are on open terms and not too bureaucratic.

The BHP boss also weighed in on the latest federal budget, which many have criticised for cutting from the least enfranchised sections of society in order to bolster certain sectors, mining included.

“We are changing the national conversation [to being] more and more about ‘what are you doing, or what have you done lately to add to national income’?” he said.