国际英语新闻：U.S. unveils nuclear forces structure

WASHINGTON, May 13 (Xinhua) -- The White House made public a " baseline nuclear force structure" on Thursday, as it sent a new arms control treaty with Russia to the Senate for ratification.

The baseline structure of U.S. strategic forces "fully supports U.S. security requirements and conforms to" limits set by the Strategic Arms Reduction Treaty (START), reached by the Obama administration and the Russian government in April, the White House said.

The baseline structure, established by Secretary of Defense Robert Gates based on recommendations from the Joint Chiefs of Staff, calls for the retaining of up to 420 deployed intercontinental ballistic missile (ICBM) silos, all with a single warhead. The START treaty allows the United States to have 450.

The United States currently has 94 deployable nuclear-capable bombers. Under the baseline plan, some will be converted to conventional-only bombers not accountable under the treaty, and up to 60 nuclear-capable bombers will be retained.

The United States currently has 14 strategic nuclear submarines (SSBNs). Under the baseline plan, all 14 will be retained. The United States will reduce the number of launch tubes from 24 to 20 per SSBN, and deploy no more than 240 launch tubes at any time.