Its recent trade agreements with Korea, China and Japan, have focused on Economic, and Technical Cooperation between those nations. Within the regional Caribbean Community and Common Market (Caricom), Colombia has also deepened Economic and Medical Science Research collaboration agreements. Colombia has also signed and ratified 105 international treaties or agreements relating to the protection of the environment. These include the Antarctic Treaty and Nuclear Test Ban Treaty and conventions on Biodiversity, Desertification, Endangered Species, Hazardous Wastes, Marine Life Conservation, Ozone Layer Protection, Ship Pollution, Tropical Timber 83, Tropical Timber 94, and Wetlands. It has signed, but not ratified, the Antarctic-Environmental Protocol and conventions on Law of the Sea and Marine Dumping. Colombia also has signed the Treaty on the Non-Proliferation of Nuclear Weapons and the Tlatelolco Treaty. By 1975 signatories to the 1974 Declaration of Ayacucho, of which Colombia was one, had decided on limitations to nuclear, biological, and chemical weapons.