In early 1983, US negotiators indicated that they would support a plan beyond the Zero Option if the plan established equal rights and limits for the US and Soviet Union, with such limits valid worldwide, and excluded British and French missile systems (as well as those of any other third party). As a temporary measure, the US negotiators also proposed a cap of 450 deployed INF warheads around the world for both the US and Soviet Union. In response, Soviet negotiators proposed that a plan would have to block all US INF deployments in Europe, cover both missiles and aircraft, include third parties, and focus primarily on Europe for it to gain Soviet backing. In the fall of 1983, just ahead of the scheduled deployment of US Pershing IIs and GLCMs, the US lowered its proposed limit on global INF deployments to 420 missiles, while the Soviet Union proposed "equal reductions": if the US cancelled the planned deployment of Pershing II and GLCM systems, the Soviet Union would reduce its own INF deployment by 572 warheads. In November 1983, after the first Pershing IIs arrived in West Germany, the Soviet Union walked out of negotiations, as it had warned it would do should the US missile deployments occur.