Israel wants Iranian recognition before it ratifies an international ban on nuclear bomb tests, an Israeli official said on Wednesday, in a rare public discussion of terms for upgrading from signatory status.

Negotiated in the 1990s, the Comprehensive Nuclear Test Ban Treaty (CTBT) enjoys wide global support but must be ratified by eight more nuclear technology states -- among them Israel, Iran, Egypt and the United States -- to come into force.

Signing the CTBT -- while stopping short of ratifying it -- has allowed Israel to engage in anti-proliferation monitoring and exercises, some involving delegates from enemy states, even as it resists foreign pressure to open up on its suspected nuclear arsenal.

"The CTBT is a treaty that Israel intends to ratify. It will do when the time is ripe, when certain considerations are met," Merav Zafary-Odiz, Israel's ambassador to the U.N. nuclear watchdog agency in Vienna, told Tel Aviv University's Institute for National Security Studies in a speech.

Among obstacles, she listed the fact that "Iran does not recognize Israel and is not willing to accept the fact that Israel belongs to its natural geographical group .. How can any country be expected to join an arms control arrangement with a country that doesn't even recognize its right to exist?"

Iranian ideological hostility to Israel is among factors spurring world powers to curb Tehran's disputed nuclear program. Negotiators are working toward a June 30 deadline for a deal under which Iran would roll back projects with bomb-making potential in exchange for sanctions relief.

Lassina Zerbo, executive secretary of the Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO), said in April that Iran could shore up its credibility by ratifying the treaty.

But, he told Reuters, "their approach is that diplomacy is always one step at a time".

By Reuters