VATICAN CITY (CNS) – The goal of politics and economics is to serve all of humanity, starting with the poorest, the most vulnerable and the unborn, Pope Francis told British Prime Minister David Cameron, president of the Group of Eight industrialized nations.

“Money and other political and economic means must serve, not rule,” the pope said, adding that “in a seemingly paradoxical way, free and disinterested solidarity is the key to the smooth functioning of the global economy.”

The pope also urged the world leaders, including U.S. President Barack Obama, to help broker an immediate cease-fire in Syria and bring warring sides to the negotiating table. The leaders were holding their annual summit at Lough Erne resort in County Fermanagh, Northern Ireland, June 17-18.

“Peace demands a far-sighted renunciation of certain claims in order to build together a more equitable and just peace,” the pope wrote, adding that peace “is an essential prerequisite” for protecting human life and eradicating hunger.

Pope Francis’ letter, released by the Vatican, was written in response to a letter Cameron sent the pope outlining some of the priorities the British prime minister intended to push during his one-year term as president of the G-8. Cameron said he wants to emphasize openness in economies, governments and societies through the support of free trade, tackling tax evasion and encouraging greater transparency and accountability in government actions.

In his reply, Pope Francis said if the work of world leaders was to have any impact, all political and economic efforts and policies must be seen as the means, not the end, with the true goal being the protection of the human person and well-being of all humanity.