Barack Obama joins world leaders at G8 summit

US President Barack Obama has arrived in Italy to join other world leaders for the G8 summit in L'Aquila. He arrived directly from Moscow after meeting Russian leaders, AFP reports.

Today's schedule includes meetings with Italian President Giorgio Napolitano and Prime Minister Silvio Berlusconi, a working lunch and Group of 8 session on global issues, and a tour of the April 6 earthquake damage. Tops on the agenda: climate change, the global economy, and development assistance for Africa, The USA Today reports.

Mr Obama and his allies are seeking an explicit commitment from all the world's largest economies to cut their emissions of carbon dioxide by 50 per cent by 2050.

But China and India have declined to agree, arguing that this would restrict their own economic development. A draft communiqué circulated on the eve of the summit omits any reference to the proposed 50 per cent cut and instead proposes concerted action to ensure that global temperatures do not rise above an average of two degrees Celsius, reports.

Meanwhile a heavy security presence is surrounding a converted police barracks where the talks would take place, and around 15,000 police officers and soldiers have been deployed in L'Aquila and Rome.

Officials are hoping to prevent a recurrence of the violence seen during the country's last G8 meeting in 2001.

Despite the police presence, protesters are continuing to gather, with more than 100 Greenpeace activists from around the world occupying four coal-fired power stations across Italy to demand action on climate change, reports.