WASHINGTON, May 26 (AFP) - The Clinton administration and congressional leaders disputed the effectiveness of response to allegations of Chinese spying after an explosive report alleging military and technical espionage by Beijing since the 1970s. The three-volume report released Tuesday by a bipartisan US congress panel states that China stole secrets to every weapon in the US nuclear arsenal, and even passed key military data to US enemies. The report by a panel headed by Representative Christopher Cox, a conservative Californian Republican, outlines a two-decade, multi-layered spy campaign by Beijing. Cox told CNN Wednesday he was surprised by claims that President Bill Clinton was unaware of the allegations until March 19. "We sent our report up on January 3," Cox told CNN. He said that if the president was uninformed until March, "it was all kept from the president. But in that case a lot of other people are lying, so its a very puzzling story." Energy Secretary Bill Richardson, whose agency supervises nuclear research labs, told NBC meanwhile, "We've taken some dramatic ... measures to beef up security at the labs, and I believe that we have taken such strong steps that right now I don't believe there's penetration." "Now the Congress needs to back me up instead of just carping away," Richardson added. Chinese espionage yielded crucial data on such items as the W-88 warhead, the neutron bomb, submarine-detection, space-weapon information, and special nuclear codes, the Cox report said. Clinton, on the defensive, said he agreed with "the overwhelming majority" of the report's recommendations, but defended his refusal to isolate China. The United States has put the strictest controls on technology transfers with China, Clinton said, adding: "We have a solemn obligation to protect such national security information and we have to do more to do it." The report states that China "has mounted a widespread effort to obtain US military technology by any means, legal or illegal" since the 1970s, Cox charged Tuesday. The thefts began in the late 1970s, continued during the 1980s and 1990s and "our report concludes it is exceptionally likely that penetration of our US national weapons laboratories continues to this very day," he said. The more than 700-page document capped an 11-month probe by the US legislators, and further strained already frayed Sino-US ties. The report details a web of tactics including using US businesses to lobby for looser export standards, exploiting public information, scientific exchanges, joint ventures with US corporations, and espionage -- much of it at US nuclear research laboratories. Security at the labs "will not meet even minimal standards until some time next year," Cox said Tuesday. China greeted the report by saying that it is based on "sheer fabrications out of ulterior political motives." "China has developed a nuclear capability through self-reliance. Our nuclear weapons are purely for defense purposes," read a three-paragraph statement from the Chinese embassy in Washington late Tuesday. "The allegations about the so-called China's 'theft' of nuclear weapons and missile secrets are sheer fabrications out of ulterior political motives. This is an attempt to stir up anti-China feelings and divert peoples attention," the statement read. However the attention of Clinton's Republican critics in Congress were well focused on trying to get top White House aides to resign. Republican House Majority Leader Dick Armey on Tuesday called on Sandy Berger, Clinton's national security advisor, to resign, saying he "failed in his duty to the administration and the American people." Earlier Republicans and some Democrats called for the ouster of US Attorney General Janet Reno -- who has jurisdiction over the FBI -- for not being forceful enough in pursuing allegations of spying at the Los Alamos National Laboratory in New Mexico. Taiwan born Wen Ho Lee was fired from his post at Los Alamos in March but has yet to be charged with a crime.  