A three-day United Nations summit, which aims to put the global economy on a more environmentally sustainable path, is getting under way in Rio de Janeiro.
The event, which opens on June 20, has been billed as a "once-in a generation" opportunity to rebalance the world economy and eradicate poverty without harming the environment.
A draft of the meeting's final text, however, has already been criticized by many delegates and environmental activists as lacking clear commitments, timetables and means of monitoring progress.
Some 90 leaders, including UN Secretary General Ban Ki-moon and French President Francois Hollande, are expected to attend the summit.
But others, including U.S. President Barack Obama, Russian President Vladimir Putin, the British prime minister and the German chancellor, will not attend and have instead sent deputies.
Based on reporting by AFP, Reuters, and guardian.co.uk