Australian journalist Peter Greste has revealed it was traumatic leaving his colleagues behind in a Cairo prison and he didn't truly believe he was being freed until he was seated on a plane bound for Cyprus.

Greste has used his first interview since being deported from Egypt to call on the country to release other detained journalists including Al Jazeera colleagues Mohamed Fahmy and Baher Mohamed.

"You spend 400 days in such close proximity with people and you really get to know them very, very well," the 49-year-old told Al Jazeera in Cyprus on Monday.

"So it was a very difficult moment walking out of that prison, saying goodbye to those guys, not knowing how much longer they will have to put up with this."

Greste said even when driving to the airport on Sunday he wondered if his ordeal was really coming to end given there'd been other moments when freedom appeared imminent but was "snatched away".

"So I really didn't want to let myself believe it really was happening until I got my backside on a seat on the plane with my brother Mike and we knew, then, that for me at least, this is over."

The Australian said the key to surviving jail had been to stay fit physically, mentally and spiritually.

Greste exercised by running, kept mentally fit by studying and remained spiritually strong through meditation.

"It was a way of enforcing a kind of discipline on myself and dealing with each day as it came," he said.

"Hopefully ... I've come out of it not too damaged."

The award-winning correspondent described his release as a massive step forward.

"I just hope that Egypt keeps going down this path with the others," he said.

"If it's appropriate for me to be free it's right for all of them to be freed."

Greste wasn't expecting to be released ahead of a scheduled retrial.

However while running on Sunday the prison warden called him over and told him to pack his things.

"I said 'What do you mean?' and he said 'You're going' and I said 'Where, to another prison?' and he said 'No the (Australian) embassy is coming they'll be here in an hour'."

Greste said he is now looking forward to "watching a few sunsets and the stars" and "feeling the sand under my toes".

Fahmy's relatives expect the Canadian-Egyptian to also be deported under a decree passed by Egypt's President Abdel Fattah al-Sisi that allows for the transfer of foreigners on trial.

Canada said Greste's release was positive and it remained "very hopeful" Fahmy would be freed soon.

Al Jazeera also vowed to pursue the campaign to free its other two journalists.

But Heather Allan, head of newsgathering at the channel, admitted she wasn't confident Mohamed, an Egyptian, would be released.

"(But) are we going to keep on fighting it? Absolutely," she said.

"We are not going to leave him there."

Mohamed's family has pinned their hopes on a presidential pardon or his acquittal on appeal.

The journalists were arrested in late 2013 for allegedly aiding the black-listed Muslim Brotherhood.

A positive for media freedom

It's hoped the outcry against Peter Greste's arrest in Egypt could spark a global movement for press freedom.

The Australian journalist has been released but two of his colleagues remain behind bars.

Amnesty International's Grant Bayldon says his release is due to a global backlash Egypt never expected to receive.

"That's the kind of backlash that we need to see for other governments that try this kind of thing."

Thousands of journalists are behind bars around the world.

Bayldon says they're are among thousands of people jailed on outrageous charges.

"Simply for criticising the government for joining peaceful protest."

CNN's Ian Lee is in Cairo and says there's optimism that the other two journalists will be released.

"Mohamed Fahmy being released possibly sooner. If he's willing to give up his dual nationality he could go the same way as Peter Greste.

"But then Baher Mohamed, his wife I talked to her, she's optimistic that if the other two go, that he'll be released as well."