Following the unexpectedly large blast of the Castle Bravo thermonuclear test of March 1954 at Bikini Atoll, there was international concern over the radioactive fallout experienced by residents of nearby Rongelap Atoll and Utirik Atoll and by a Japanese fishing vessel. The AEC initially tried to keep the contamination secret, and then tried to minimize the health dangers of fallout. Voices began to be heard advocating for a ban or limitation on atmospheric testing of nuclear weapons. Strauss himself downplayed dangers from fallout and insisted that it was vital that a program of atmospheric blasts proceed unhindered. However, Strauss also contributed to public fears when, during a March 1954 press conference, he made an impromptu remark that a single Soviet H-bomb could destroy the New York metropolitan area. This statement was heard overseas as well and served to add to what UK Minister of Defence Harold Macmillan termed a "panic" over the subject. The AEC had commissioned the Project SUNSHINE report in 1953 to ascertain the impact of radioactive fallout, generated from repeated nuclear detonations of greater and greater yield, on the world's population. The British asked the AEC for the report, but Strauss resisted giving them anything more than a heavily redacted version, leading to frustration on the part of Prime Minister Winston Churchill and other UK officials.