The Latest on the Vatican nuclear conference (all times local):

12:30 p.m.

The head of the Nobel Peace Prize-winning International Campaign to Abolish Nuclear Weapons says a new U.N. treaty calling for the elimination of atomic weapons will have an effect even on the nuclear powers that refused to sign on.

Beatrice Fihn says previous treaties banning chemical and biological weapons were a crucial first step in making such arsenals illegal, and putting pressure on countries that had the weapons to disarm.

Speaking on the sidelines of a Vatican disarmament conference Friday, Fihn has told The Associated Press: "If international law says it's prohibited, it's going to make it a lot harder for them (nuclear weapons states) to justify their decisions to modernize and invest in new types of weapons."

Fihn's group won the Nobel this year for its instrumental role in galvanizing support for the U.N. treaty.


9 a.m.

The Vatican is hosting Nobel laureates, U.N. and NATO officials and a handful of nuclear powers at a conference aimed at galvanizing support for a global shift from the Cold War era policy of nuclear deterrence to one of total nuclear disarmament.

Pope Francis is due to address the conference Friday, adding his voice to the campaign that produced a new U.N. treaty calling for the elimination of atomic weapons, and a Nobel Peace Prize for the small advocacy group that was instrumental in pushing the treaty through.

Among those speaking at the two-day meeting are Beatrice Fihn, executive director of the Nobel-winning International Campaign to Abolish Nuclear Weapons, and Masako Wada, who survived the atomic bombing of Nagasaki and has gone onto become a prominent disarmament activist.