"Political transformation is needed," a written statement said, but "it is not a precondition for ending violence; rather it will accompany the cessation of violence and the rebuilding of trust."
Once greater trust and cooperation are built, "new political forms in Syria are needed to ensure representation, participation, reform and the voice and security of all social groups," it said.
The statement was based on what came out of a day-long closed-door workshop hosted Jan.13 by the Pontifical Academy for Sciences.
Jesuit Father Federico Lombardi, Vatican spokesman, said the initiative was a "brainstorming" session meant to gather ideas for Pope Francis and not form an official Vatican position.
The statement, which was addressed to Pope Francis, was also meant to help inform leaders taking part in United Nations-backed peace talks being held in Geneva Jan. 22.
Seven international experts and leaders -- including former Egyptian Vice President Mohamed ElBaradei and U.S. economist and adviser Jeffrey Sachs -- attended and explained the different positions of some of the major players involved in the conflict.
The only invited speaker unable to attend was former British Prime Minister Tony Blair who canceled at the last minute due to an unavoidable, conflicting engagement, according to the academy.
Nearly two dozen people were invited as observers; they included ambassadors to the Vatican and religious leaders representing the Catholic Church and the Russian Orthodox Church.
One of the observers, Archbishop Silvano Tomasi, the Vatican observer at U.N. agencies in Geneva, told Vatican Radio that the recommendations coming from the day's discussions would be offered to those taking part in the so-called Geneva 2 peace talks.
Those peace talks, in order to be successful, the statement said, will have to make sure there is "inclusive participation of all parties to this conflict, within the region and beyond."
The recommendations, detailed in the Vatican statement, begin with an immediate cease-fire and an end to the funding and supplying of weapons by foreign countries to all sides in the conflict.
The next step needs to be "the immediate start of humanitarian assistance and reconstruction," it said. Both rebuilding the nation and the cease-fire need to start "even before all the political and social questions are resolved," it said.
People of all religions need to play a role in repairing communities and the spiritual fabric of the country so the people there can "reach a new understanding and significant restoration of trust after years of inter-communal violence," it said.
"The conflict in Syria has drawn its violent force from the conflicts and deep distrust in the region," it said.
Therefore, successful and long-lasting peace in Syria, it said, will only come when it's built on addressing and resolving all the violence and rivalries tearing apart the region.
Rebuilding trust and cooperation between Iran and other nations and the success of an interim agreement over Iran's nuclear program will help "provide a vital foundation for a lasting peace in Syria," it said.
"So too would a breakthrough in the ongoing Israeli-Palestinian peace negotiations being facilitated by the United States," it added.
An immediate cease-fire, the resumption of dialogue, rebuilding efforts, a resolution to regional conflicts and the full participation of all sides in upcoming peace talks in Geneva would "provide a base of security and reconstruction upon which lasting peace can be built," it said.
Syria's brutal civil war has left at least 100,000 people dead, 6.5 million people displaced inside Syria and forced nearly 2.5 million people to flee the country.
The three-year conflict has hurt assistance and humanitarian efforts on the ground because of the lack of security, blocked access and insufficient resources inside Syria.
In his speech to diplomats Jan. 13, Pope Francis said what is needed is "a renewed political will to end the conflict" in Syria.
He said he hoped the Geneva peace talks "will mark the beginning of the desired peace process. At the same time, full respect for humanitarian law remains essential. It is unacceptable that unarmed civilians, especially children, become targets."
He also encouraged everyone to make sure urgently needed aid could reach all Syrians, and he praised those countries, "especially Lebanon and Jordan, which have generously welcomed to their territory numerous refugees from Syria."