By EDITH M. LEDERER
UNITED NATIONS (AP) — The new head of the U.N. nuclear test ban treaty organization says his goal is to have the treaty enter into force, which would require ratification by eight countries — the United States, China, Iran, Israel, Egypt, India, Pakistan and North Korea. Robert Floyd said at a news conference Wednesday: “I remain optimistic, but I’m also realistic. I don’t underestimate the challenge.” The Comprehensive Nuclear Test Ban Treaty has 196 member states — 185 that have signed the treaty and 170 that have ratified it. But it needs the eight non-ratifying countries that had nuclear power reactors or research reactors in 1996 before it can take effect.