VIENNA – The head of the UN atomic watchdog is asking for international input on an Arab-led push to have Israel join the Nonproliferation Treaty, in a move that adds to pressure on the Jewish state to disclose its unacknowledged nuclear arsenal. Israel, in turn, is suggesting the push is misdirected and the International Atomic Energy Agency should focus instead on giving teeth to the nuclear treaty to prevent signatories like Iran from acquiring such weapons. Israel's response follows publication of a letter Wednesday from IAEA chief Yukiya Amano. Amano asked foreign ministers of the IAEA's 151 member states to share views on how to implement a resolution demanding that Israel "accede to the" Nonproliferation Treaty and throw its nuclear facilities open to IAEA oversight. In response Thursday, an Israeli official said the onus should be on beefing up the Nonproliferation Treaty, noting that even treaty signatories — like Iraq — have tried in the past to gain nuclear weapons. Iran, also a treaty member, is "now doing the same," said the official, who spoke on condition of anonymity because of Israel's policy of ambiguity on its nuclear capabilities. Israel has never acknowledged or denied having nuclear weapons but is widely believed to possess them. Egypt has proposed that a Nonproliferation Treaty conference now meeting at UN headquarters in New York back a plan calling for the start of negotiations next year on a Mideast free of nuclear arms. The proposal may become a major debating point in the monthlong session. The US has cautiously supported the idea while saying that implementing it must wait for progress in the Middle East peace process. Israel also says a comprehensive Middle East peace settlement must come first. "The question is, how do you do that in the absence of a peace plan?" Undersecretary of State Ellen Tauscher said Wednesday of the "nuke-free" zone idea. Still, Washington appears to be ready to move from passive support to a more active role. In her speech to the UN nuclear conference on Monday, Secretary of State Hillary Rodham Clinton said Washington would support "practical measures for moving toward that objective," while Tauscher said the U.S. has been working "for months" with Egypt on the issue. Washington also has been discussing it with the Israelis, said another Western diplomatic source, who asked for anonymity since he was discussing other countries' contacts. Amano's April 7 letter comes seven months after IAEA member states at their annual Vienna conference narrowly passed a resolution directly criticizing Israel and its atomic program, with 49 of the 110 nations present backing the document, 45 against and 16 abstaining. The result was a setback not only for Israel but also for Washington and other backers of the Jewish state, which had lobbied for 18 years of past practice — debate on the issue without a vote. It also reflected building tensions between Israel and its backers and Islamic nations, supported by developing countries. The resolution "expresses concern about the Israeli nuclear capabilities," and links it to "concern about the threat posed by the proliferation of nuclear weapons for the security and stability of the Middle East." The US and its allies consider Iran the region's greatest proliferation threat, fearing that Tehran is trying to achieve the capacity to make nuclear weapons despite its assertion that it is only building a civilian program to generate power.