The Pope expressed the hope that the conference would “be the start of a path towards an end to violence and a negotiated solution leading to peace and much-desired stability in the country.”
The UN estimates that the country's conflict has killed hundreds of people and displaced thousands more.
Germany is bringing together the key players in Libya's long-running civil war in a bid to determine the North African nation's future.
Also in attendence is Russian President Vladimir Putin, Turkish President Recep Tayyip Erdogan, the UK's Boris Johnson and the UN.
As talks continued on Sunday there was a call for all parties to refrain from hostilities against oil facilities.
Conflict has been rife in Libya since the 2011 uprising which ousted long-time leader Muammar Gaddafi.
A truce was announced earlier this month between Gen Khalifa Haftar's Libyan National Army (LNA) and the rival and UN backed Government of National Accord (GNA), led by Prime Minister Fayez al-Serraj. However, both sides have blamed eachother for breaches of the accord.