WASHINGTON - Scientist Stewart David Nozette appeared in court here Tuesday on charges that he attempted to sell US national security secrets to Israel. Nozette was jailed without bond and accused in a criminal complaint of two counts of attempting to communicate, deliver and transmit classified information. The accused, wearing jeans and an untucked blue oxford shirt with no tie, didn't speak at the proceeding or enter a plea. He faces a life sentence if convicted on two counts of unlawfully attempting to provide defense information to aid a foreign nation. Nozette "has shown a willingness and desire to sell some of our nation's most closely guarded secrets," Assistant US Attorney Anthony Asuncion said, adding that disclosure of the material could cause "exceptional grave damage to national security." Asuncion described Nozette as a flight risk who had told a colleague he would flee to Israel if the government ever tried to arrest him. Nozette, a top US physicist with access to nuclear secrets, was arrested in a sting operation in which an undercover FBI agent posed as a Mossad handler beginning in September, the US Department of Justice announced late on Monday. According to the affidavit, Nozette allegedly agreed to sell the handler highly sensitive information in return for money and an Israeli passport. Spokesmen for the Prime Minister's Office, the Foreign Ministry and the Israeli Embassy in Washington declined to comment on the matter, with several sources saying they had received no prior notification about the case. "The first we heard about this was in the media," one senior government official said, pointing out that Israel had no role in the case and therefore did not need to issue a response. The official even distanced himself from statements attributed to a government official on Israeli Radio that Israel did not engage in espionage activities in friendly countries, saying such a comment was superfluous since no one was accusing Israel of such activity. US State Department spokesman Ian Kelly also declined to comment, saying he did not know whether US officials had been in touch with their Israeli counterparts in connection with the development. "As a general principle, we're always concerned when there is any suggestion of transfer of sensitive national security information," he said when pressed during a media briefing. According to the affidavit, Nozette has held "top-secret" security clearances including for sensitive nuclear information. He also, during the past decade, worked as "a technical consultant for an aerospace company that was wholly owned by the government of the State of Israel." This fall, after the US government noted that Nozette had made a suspicious trip abroad, carrying with him two computer thumb drives that he did not return to work, the scientist was approached by the undercover agent. The affidavit claims that agents arranged for Nozette to drop off classified information in a "dead drop" at a Washington post office. Though he initially expressed some skepticism about the nature of his handler, he described the dead drop routine as "kind of Mossad-like." In two drops over the past six weeks, Nozette provided encrypted sensitive defense information in return for $11,000, and also supplied signatures and photos of himself for the Israeli passport he had requested, the affidavit states. The affidavit also provides transcripts of conversations Nozette had with the undercover agent, in which Nozette described his desire for money and the passport. "My parents are Jewish," he allegedly told the agent. "So I have a right, theoretically I have the right of return." He asked about getting an Israeli passport "because if I'm gonna work I wouldn't mind having another base of operations outside the US to work out of." According to the taped conversation, only brief excerpts of which were provided in the 18-page affidavit, Nozette expected to be recruited by Israel since he had been working on sensitive defense information as part of his job consulting for the Israeli-owned company for the last decade. "I knew this day would come," he allegedly said. "I knew you guys would show up." The affidavit also quotes him as saying, "I thought I was working for you already. I mean that's what I always thought, [the foreign company] was just a front." Though the affidavit doesn't name the business, press reports have identified it as Israel Aerospace Industries. Nozette, a 52-year-old Chicago-born resident of Maryland, was involved in US missile defense technology during his time in government and is credited with helping discover water on the moon. Neither he nor his lawyer could be reached by The Jerusalem Post. Herb Keinon and news agencies contributed to this report.