Prime Minister Tony Abbott has sent the Indonesian president a letter addressing the spy scandal.

Prime Minister Tony Abbott is remaining tight-lipped about the contents of his letter to the Indonesian president about the spy scandal.

Susilo Bambang Yudhoyono had written to Mr Abbott demanding an official apology and a full explanation as to why Australian spies in 2009 targeted his mobile phone, as well as his wife’s and some of his closest confidants.

Indonesia has halted all co-operation with Australia on people smuggling following the phone-tapping controversy.

Mr Abbott told reporters in Sydney on Saturday that he had written to Dr Yudhoyono.

“The letter is now in the process of being delivered,” he said.

“I think it would be wrong of me to talk about what I’ve said to the president before the president has actually received it.”

Mr Abbott reiterated the government’s commitment to a strong relationship between Australia and Indonesia.

“Obviously there will be good days and there will be better days but my determination is to ensure that the relationship is constantly improving,” he said.

Tear gas was used to repel protesters on Friday during demonstrations in Jakarta over the spy row.

An Australian flag and pictures of Mr Abbott were set alight.

The Australian embassy was pelted with rocks and eggs, and a mock coffin bearing a photo of Mr Abbott was left on the road in front of the compound.

Dr Yudhoyono tweeted on Saturday that social relations are closer when there is mutual trust, care and co-operation.