Toyota will not receive extra taxpayer support to remain in Australia, despite fears it could yet follow Holden out the door, Tony Abbott has revealed.

The Prime Minister said he expected the Japanese car maker, which employs 4200 people, would stay because it had a strong export business. He said Canberra would not go beyond the assistance set out in the Automotive Transformation Scheme and dismissed calls for an increase to safeguard jobs as ''not the right way to go''.

He said ''the lesson of the motor industry is that once you start subsidising businesses you get yourself onto a treadmill.

The uncompromising attitude was reflected in frank observations on foreign policy but broke down when he acknowledged mistakes on school funding policy a fortnight ago. The comments came in an interview with Fairfax Media marking 100 days in office.

Referring to the decision first to dump, then recommit to the Gonski school funding model, he said he had learnt on the job.

''The lesson that I have well and truly learnt from that is that we do have to precisely honour our commitments and that's the spirit of the commitments, not just the letter of the commitments.''

That was a marked softening of his declaration during the furore that he would not be held to promises people thought he had made. Speaking in his Parliament House office, he said he wanted Australia to continue making cars but added: ''If the price of keeping the car industry is unacceptably high, well, you just have to accept that these are the trade-offs that life sometimes involves''.

''I think there's every chance that we can keep Toyota but the level of assistance that Toyota can expect is roughly the same level of assistance that they have previously received,'' he said. He said General Motors' decision to pull out in 2017 reinforced the importance of reducing the tax and regulatory burden for business, and increasing productivity. ''On all three, the government is on the side of the angels,'' he said.

Despite polls showing voter disappointment, Mr Abbott said he was pleased with the Coalition's performance. He rejected criticism that his administration had been slow to manage problems as they arose, arguing it was ''better to get the decision as right as it can be than to rush into something which you might subsequently regret''.

''I am utterly unpersuaded that we could have done anything differently for a substantially better outcome,'' he said.

But there was frustration that Labor ''had not accepted the government's mandate'' on the carbon tax, mining tax and border protection. ''While Labor might have got some short-term satisfaction from that, I think it's going to do them long-term damage with the public,'' he said.

Some of his bluntest language was reserved for China, which he accused of upsetting the regional balance, and for Jakarta after the spying scandal, to which he directed the message that its best friend was Australia.

Australia wanted to have the best relations with Beijing but if it acted high-handedly, the government would speak up. He said border protection was non-negotiable. ''That's something the Indonesians just have to accept''.