On Tuesday, Pope Francis acknowledged the difficulty of totally eliminating nuclear weapons, but said the challenge is still a necessary undertaking, especially given what's at stake.

"The ultimate goal of the total elimination of nuclear weapons becomes both a challenge and a moral and humanitarian imperative," he said in a message to United Nations members March 28.

The message was read before the "United Nations conference aimed at negotiating a legally binding instrument on the prohibition of nuclear weapons, leading to their total elimination," held in New York March 27-31.

Presented by Msgr. Antoine Camilleri, Secretary for Relations with States and head of the Holy See's delegation at the meetings, the Pope's message acknowledged that the goal is a "demanding" and "forward-looking" one.

And this is true especially given the present international climate, which is both "cause and indication" of the difficulties of furthering and strengthening a nuclear ban, he said.

"If we take into consideration the principal threats to peace and security," he continued, "for example, terrorism, asymmetrical conflicts, cybersecurity, environmental problems, poverty, not a few doubts arise regarding the inadequacy of nuclear deterrence as an effective response to such challenges."

These combined with the "catastrophic humanitarian and environmental consequences" that would follow the use of nuclear weapons make the goal a moral and ethical necessity, he said.

Additionally, the resources spent on nuclear weapon development could be used for more worthy causes, such as poverty, and the promotion of peace and integral human development.  

Considered to be only the first part of UN meetings to ban and eventually eliminate nuclear weapons, the talks are supported by more than 120 countries, as well as numerous disarmament groups.

On the other hand, more than 40 countries have declined to participate in the talks, including the United States and most other nuclear powers, such as Britain and Russia.

On Monday, U.S. Ambassador Nikki R. Haley led a group of dozens of UN members in boycotting the discussions, saying she did not think that it was the right time to have these talks given the unlikeliness of North Korea banning nuclear weapons, according to the New York Times.

In his message, Pope Francis said the conference "intends to negotiate a Treaty inspired by ethical and moral arguments."

"It is an exercise in hope and it is my wish that it may also constitute a decisive step along the road towards a world without nuclear weapons. Although this is a significantly complex and long-term goal, it is not beyond our reach," he said.

"International peace and stability cannot be based on a false sense of security, on the threat of mutual destruction or total annihilation, or on simply maintaining a balance of power."