The conference to negotiate a legally binding treaty to ban nuclear weapons begins at the United Nations headquarters in New York on Monday. But all the nuclear states will not participate.The UN General Assembly voted to start negotiations last December. More than 50 non-nuclear countries submitted the proposal and 113 states supported the resolution.The treaty is to ban nuclear weapons based on the interpretation they are in breach of international laws.More than 100 countries are expected to take part in the negotiations. They will likely focus on how to substantiate the illegality of nuclear weapons.The United States and Russia say the negotiations lack the realistic perspective of international security.Japan is the only country to have experienced atomic bombings, but has also been against the treaty. The government's position is that disarmament should occur in stages with cooperation of both nuclear and non-nuclear states.Japan is arranging to send an envoy to speak at the conference, but is unlikely to take part in the negotiations.Swedish Foreign Minister Margot Wallstrom told NHK at the UN on Thursday that the negotiations are timely. She said there have recently been comments flaunting nuclear arms. She added that many countries are frustrated with the stalemate in nuclear arms reduction.Former US President Barack Obama called for "a world without nuclear weapons." His successor Donald Trump has indicated he wants to strengthen US nuclear power.