ROME — From the beginning of his pontificate, Francis has aspired to be a “Peace Pope,” and in two major messages this week he issued strong pleas for both nuclear disarmament and putting an end to human trafficking, the modern equivalent of the slave trade.

“Nuclear deterrence and the threat of mutually assured destruction cannot be the basis for an ethics of fraternity and peaceful coexistence among peoples and states,” the pontiff said in a message read aloud by an aide to a conference on the “Humanitarian Impact of Nuclear Weapons” in Vienna, Austria, on December 8-9.

The conference was hosted by the Austrian government and organized in collaboration with a variety of humanitarian groups. It was the third in a series, and in the past, nations possessing nuclear arms typically have boycotted. This time, however, the United States, the United Kingdom, and China all participated, though with reservations.

In his message, Francis denounced nuclear weapons as a “global problem” affecting all nations and imperiling both future generations and the planet.

“I am convinced that the desire for peace and fraternity planted deep in the human heart will bear fruit in concrete ways to ensure that nuclear weapons are banned once and for all, to the benefit of our common home,” he said.

The message was presented by Italian Archbishop Silvano Maria Tomasi, the Vatican’s permanent observer at the United Nations in Geneva.

Although it was Pope Francis’ first statement nuclear weapons, it largely confirmed the Vatican’s long-standing advocacy for verifiable mutual disarmament.

In the 1965 document Gaudium et Spes [“Joy and Hope”], the Second Vatican Council declared that “any act of war aimed indiscriminately at the destruction of entire cities or extensive areas along with their population is a crime against God and man himself.”

“It merits unhesitating condemnation,” the bishops at Vatican II said.

In his statement to the Vienna summit, Francis said nuclear nations have to move beyond paying lip service to the idea of the abolition, expressed in the 1970 Treaty on the Non-Proliferation of Nuclear Weapons, and take the next steps toward making it real.

“The humanitarian consequences of nuclear weapons are predictable and planetary,” the pope said.

Representatives of more than 150 countries participated in the Vienna conference, including a group of Hibakusha — survivors of Hiroshima and Nagasaki — and victims of nuclear testing.

“Peace must be built on justice, socioeconomic development, freedom, [and] respect for fundamental human rights,” the pope said.

These concepts were also present on the message released Wednesday by the Vatican for the celebration of the “World Day of Peace,” which the Catholic Church commemorates on January 1.

Titled “No longer slaves, but brothers and sisters,” the document is the latest appeal by Francis to put an end to human slavery, including organ trafficking, forced prostitution, and the forced recruitment of minors as soldiers.

The pope said trafficking is rooted in an objectivized notion of the human person that leads to a “rejection of another person’s humanity,” alongside poverty, underdevelopment, exclusion, lack of access to education, scarce employment opportunities, armed conflicts, violence, criminal activity, terrorism, and corruption.

For Francis, who has made the push against human trafficking one of the pillars of his pontificate, states and intergovernmental agencies are not the only ones that have to fight this “crime against humanity.”

The six-page document emphasizes individual social responsibility, appealing for consumers to avoid buying goods that may have been produced by exploited workers as opposed to placing all the responsibility on governmental agencies.

“Every person ought to have the awareness that purchasing is always a moral and not simply an economic act,” the pope wrote.

“We ought to recognize,” Francis wrote, “that we are facing a global phenomenon which exceeds the competence of any community or country.

“In order to eliminate it, we need a mobilization comparable in size to that of the phenomenon itself,” he said.