The Heads of State and Government , while noting the entry into force of the 2002 Moscow Treaty between the Russian Federation and the United States , stressed that reductions in deployments and in operational status can not substitute for irreversible cuts in , and the total elimination of , nuclear weapons , and called on the United States and the Russian Federation to apply the principles of transparency , irreversibility and verifiability to further reduce their nuclear arsenals , both warheads and delivery systems , under the Treaty . While taking note of the positive signals by the United States and the Russian Federation on their negotiations on the replacement of the Strategic Arms Reduction Treaty ( START I ) , which is due to expire by the end of 2009 , the Heads of State and Government urged them to conclude such negotiations urgently in order to achieve further deep cuts in their strategic and tactical nuclear weapons .