ISRAEL says the economic pressure that appears to have brought a dramatic breakthrough in nuclear negotiations with North Korea is unlikely to work on Iran. This gloomy assessment delivered by Israel's deputy foreign minister on Thursday came ahead of a key visit to the White House by Prime Minister Benjamin Netanyahu. The Israeli leader is expected to argue that economic sanctions are not stopping Iran from moving ahead on developing nuclear weapons, and that military strikes should be considered a viable option. On the eve of the trip, another country under pressure for its nuclear programme -- North Korea -- announced that it would cease uranium enrichment and missile tests in exchange for US food aid. The deal is seen as a success for sanctions imposed on Pyongyang. In a radio interview, Deputy Foreign Minister Danny Ayalon cautioned against drawing parallels, saying North Korea is more susceptible to international pressure than Iran. "North Korea is a small and weak state," Ayalon told Israel's Army Radio station. "If it had a nuclear bomb or two in its cellar it was only for economic blackmail. Iran has global ambitions, with ideological motivations. And it is a direct threat on its (regional) environment." Tehran says its nuclear programme is aimed at peaceful uses like power generation and cancer treatment, but Israel, the US and other Western countries all believe that Iran is developing the capability to build a weapon. Despite the agreement over Iran's goals, sharp differences have emerged between the allies over how to respond. Israel has argued that time is running out to stop Iran, and that it could soon be compelled to carry out a military strike against Tehran's nuclear installations. The US and its European partners say economic sanctions set to go into effect this summer must be given time to work, though they have not ruled out military action. There are concerns that an Israeli attack on Iranian nuclear facilities could prompt missile strikes against Israel either by Iran or from its Lebanese proxy Hezbollah, as well as rocket attacks by Hamas in Gaza. On Thursday, state-run Israel Aerospace Industries announced that it would be testing an advanced missile interceptor system, the Arrow 3, "in the near future". The joint US-Israel Arrow system is designed to bring down ballistic missiles far from their targets. "Arrow 3, the improved model of the Arrow system...is more capable than ever to deal with future threats," said Itzhak Kaya, head of the Arrow missile program. Israeli Defense Minister Ehud Barak has been in Washington this week for talks with top US security officials. North Korean leader Kim Jong-un announced Wednesday that his country would stop nuclear weapons testing, freeze uranium enrichment, and allow foreign inspectors to visit its nuclear sites. In exchange, the United States promised to deliver more than 200,000 tons of food aid. Although the announcement falls short of ending the North Korean nuclear programme, it signals a long-awaited victory for Washington's use of economic pressure. North Korea faces tough UN sanctions that were tightened in 2009 when it conducted its second nuclear test and launched a long-range rocket. Millions continue to go hungry, according to the World Food Programme. North Korea is also in a state of transition following the death of its longtime leader, Kim Jong Il, in December. Kim's untested son, Kim Jong Un, was subsequently named the reclusive nation's leader. Although Iran's nuclear programme is not believed to be as advanced as North Korea's, analysts said the Tehran regime is far more entrenched. Hazhir Temourian, an Iran expert at the Limehouse Group of Analysts in London, said the leadership change in North Korea provided an opportunity to pursue a more moderate policy. In contrast, he said "there is no sign" that Iran's supreme leader, Ayatollah Ali Khameini, "wants to share any power". Eldad Pardo, an expert on Iran at the Hebrew University in Jerusalem, said North Korea and Iran appear to be going in different directions. North Korea is one of the last holdovers of communism, long cut off from its former patrons China and the disbanded Soviet Union, he said. But Iran, he said, is "the wave of the future". "If you look across the Middle East, they started as one Islamic regime and now you have Islamic regimes all over," he said. The nuclear programme boosts Iran's rising profile, he added. "Therefore it is harder for the Iranians to compromise." This article is by Daniella Cheslow of the Associated Press