Alfonso Garcia Robles explained how the Mexican delegation tried to gather the support of the Latin American countries for the NPT draft. These countries prepared and presented modifications to the NPT text, and the United States and the Soviet Union accepted some of these proposals. Garcia Robles reported that the Argentinian and Brazilian representatives said they recognized the value of the NPT but would not support it if it kept its clause prohibiting peaceful nuclear explosions. The Ambassador also reported the Soviet positive reactions toward the Treaty of Tlatelolco. Garcia Robles recounted the skepticism of some delegations toward the NPT. He recommended not to sign the NPT in 1968 unless the Soviet Union signed Protocol II of the Treaty of Tlatelolco, which includes negative security assurances.