LONDON -- Freed Al Jazeera journalist Peter Greste says it is too early to celebrate his liberty because his two colleagues still face retrial in Egypt.

Greste was freed from an Egyptian prison earlier this month and his colleagues were released last week. He said Thursday that the controversial court cases seem to be moving in the right direction.

Greste, an Australian, had initially been sentenced to seven years in prison for spreading false information and helping the outlawed Muslim Brotherhood. He was deported from Egypt upon his release.

Colleagues Mohamed Fahmy and Baher Mohammed are still in Egypt and are required to report regularly to the police ahead of a retrial expected to begin next week.

Their imprisonment for more than a year was seen by many as a direct threat to press freedom and sparked numerous protests around the world.

Greste warned at London's Frontline Club that their case highlights the need for vigilance against further infringement of press freedom at a time when militant radicals are committing violent acts against journalists and some governments are taking "draconian" actions against the press.

He said the recent beheadings of journalists held hostage by extremists and the slaying of journalists at satirical weekly Charlie Hebdo are pressuring the media to "avoid certain bits of society and I think that's incredibly dangerous."

Greste said he used meditation, running and study to try to maintain his mental and physical well-being while imprisoned in Egypt. He said he is not bitter or angry about what happened to him and that he plans to continue his journalistic work.