Mexico City, Sep 9 (DPA) Noting that disarmament is back on the global agenda, UN Secretary-General Ban Ki-moon cautioned Wednesday that the 'world is over-armed and peace is under-funded'.

Ban opened a disarmament conference at the former convent of San Hipolito in central Mexico City, and said that there are more than 20,000 nuclear weapons around the world, and that many of them may even be activated any time.

Despite the challenges, Ban said he was hopeful for the future, adding that he had high expectations for a UN Security Council meeting on non-proliferation and nuclear disarmament Sep 24.

The UN-sponsored annual conference on disarmament was set to be attended by delegates from 70 countries and representatives of 1,700 NGOs.

The outcome of the discussions, which will range from better monitoring of small arms to getting rid of arsenals of nuclear weapons, would contribute to the review of the Nuclear Non-Proliferation Treaty at the UN next year and other disarmament debates.