I am happy to note your suggestion that you are prepared to negotiate a treaty banning nuclear tests in the atmosphere, in outer space and under water in the immediate future./1/ Now that the subcommittee on nuclear test ban is continuing in session throughout the recess in the 18-Nation Disarmament Conference, I think we should make a serious effort to work out such an agreement in time to meet the target date of January 1, 1963, which both sides have mentioned in the Geneva negotiations. We have prepared such a treaty,/2/ and our representatives and those of the United Kingdom will be working with yours in the subcommittee to get the earliest possible agreement on a final text.

While we are negotiating toward a limited ban of this type we should at the same time be negotiating towards a treaty for banning nuclear weapons tests in all environments. As part of this effort we could be working to eliminate the difference of view as to a question of scientific fact which has so far kept our negotiators apart. Our scientists advise me that although substantial progress has been made in detecting and identifying nuclear explosions on the basis of instrumentation, it is not possible to do so on a basis which renders the requirement of on-site inspections unnecessary. Your delegation has taken the opposing view but has not supplied any scientific information which may have led your government to hold this view. A joint working party of your scientists together with ours and scientists from the United Kingdom might be able, finally, to dispel the differences which have so far blocked our efforts to obtain agreement.
I believe that when we have prepared and put into effect a treaty banning tests in the atmosphere, in outer space and under water, we can then look at the problem of continued testing under ground and take such steps as we may then determine seem most likely to be helpful in arriving at a comprehensive treaty in the light of the progress which has been made at that time.
In your message you mention the role that France should play in the treaty. Of course, our comprehensive treaty draft provides that the United States, the United Kingdom, and the Soviet Union shall cooperate in encouraging other states to become parties to the treaty. For its part, the United States would work in close consultation with France and would hope that France would adhere to the treaty. Indeed, both you and we have a great interest in assuring the adherence to the treaty of all states or authorities capable of conducting a nuclear weapons test. Without their adherence the treaty could not endure.
A test ban agreement, together with an agreement on the nondissemination of nuclear weapons of the kind which Secretary Rusk had discussed with Ambassador Dobrynin,/3/ would have a powerful effect in deterring the spread of nuclear weapons capabilities to other countries. I firmly believe that obtaining this objective is in our mutual interest. It cannot be in the security interest of any of us if the present small number of nuclear powers is expanded, for, to the extent this is the case, the possibilities of war by accident or by design can only increase. There is still time to put an effective end to this threat.