A major conference drawing representatives from more than 140 countries ended Friday with an appeal for action to outlaw nuclear weapons ahead of the 70th anniversary of the atomic bombings of Hiroshima and Nagasaki next year.

The chair's summary of the two-day Second Conference on the Humanitarian Impact of Nuclear Weapons in Nayarit, Mexico, repeated the growing risk of nuclear weapons use globally because of their proliferation and vulnerability to cyberattacks, human error and potential access to nuclear arsenals by terrorist groups.

In addition to the short- and long-term impact on human health from radiation exposure, a nuclear weapon detonation would have effects not constrained by national borders, most severely affecting the poor and vulnerable, the document said.