Mobile ICBMs are not covered. The Soviet Union considered that, since neither party was renouncing these systems, it should not be subject to a freeze; it also refused to ban them in a future comprehensive agreement. The United States considered that it should be banned because of the control difficulties it presented. In an official statement, the U.S. delegation said that the United States would consider the deployment of land-based mobile ICBMs during the period of the agreement to be inconsistent with its objectives. On June 18, 1979, an agreement to limit strategic launchers was reached in Vienna, signed by Leonid Brezhnev and Carter at a ceremony in the Redouten Hall of the Imperial Hofburg.  Two initial disagreements were obstacles. Soviet officials tried to define as „strategic“ any American or Soviet weapons system capable of reaching the territory of the other party – that is, negotiable in SALT. It would be a system based on the United States, mainly short- and medium-range bombers stationed on aircraft carriers or in Europe, but it would have excluded, for example, Soviet medium-range missiles directed towards Western Europe. The United States decided that salt-negotiated weapons included intercontinental systems.
Its forward-facing armed forces were used to fight Soviet medium-range missiles and aircraft aimed at American allies. Accepting the Soviet approach would have had an impact on the alliance`s commitments. Even after the Vladivostok agreements, the two nations were unable to resolve the other two outstanding issues of SALT I: the number of strategic bombers and the total number of warheads in each nation`s arsenal. The first was made more difficult by the Soviet Bomber Backfire, which American negotiators thought could reach the United States, but which the Soviets did not want to include in the SALT negotiations. Meanwhile, the Soviets tried unsuccessfully to limit the American use of cruise air missiles (ALCMs). The audit also divided the two nations, but they eventually agreed on the use of National Technical Means (NTM), including the collection of electronic signals known as telemetry and the use of photo recognition satellites. On June 17, 1979, Carter and Brezhnev signed the SALT II Treaty in Vienna. Salt II limited the total number of nuclear forces from both countries to 2,250 delivery vehicles and imposed numerous additional restrictions on core strategic forces, including MIRVs.