WASHINGTON - The Obama administration welcomed Japan's Yukiya Amano as the next head of the UN's nuclear watchdog Friday, as months of deadlock finally produced a leader seen as amenable to Washington's agenda. Amano succeeds Nobel Peace laureate Mohamed ElBaradei as the head of the UN's International Atomic Energy Agency, a tenure marked by tensions with the US and Israel as officials in both countries questioned his commitment to stopping Iran's nuclear drive and expressed frustration at activism that often ran against their own approaches. "For the international community, the IAEA represents the premier international institution for promoting the safe and secure application of nuclear energy in the pursuit of prosperity, and working jointly on global challenges such as nuclear terrorism and proliferation," said US Secretary of State Hillary Clinton in a statement released Friday. "In selecting Ambassador Amano, the member states of the IAEA reiterate their common resolve to collaborate on these pressing issues." The US had a strong preference for Amano, who has been viewed by American officials as a technocrat willing to pursuing a hard line on Iran's nuclear ambitions. Despite American support, Amano, in brief remarks to reporters after winning the contested vote, did not shy away from recalling the devastation US atom bombs wreaked on his country in pledging to do his utmost to prevent the spread of nuclear arms. Amano's allusions to the bombings of Hiroshima and Nagasaki pointed to a deep commitment to nonproliferation. Japan, which is separated from North Korea only by a narrow body of water, keenly shares the United States' concerns about Pyongyang's nuclear program. On Saturday, the US condemned North Korea's firing of seven short-range missiles earlier in the day, according to South Korean officials monitoring the situation, continuing to ratchet up tensions with its neighbors and the West over its missile and nuclear program. "North Korea should refrain from actions that aggravate tensions and instead focus on denuclearization talks and implementation of its commitments" from 2005 to abandon nuclear weapons, said State Department spokesman Karl Duckworth. North Korea left the nonproliferation fold to develop a nuclear weapons program on ElBaradei's watch and his agency later launched inconclusive probes on suspicions that it was interested in developing nuclear weapons. Thursday's decision by the 35-nation International Atomic Energy Agency board ended a tug of war on who should succeed ElBaradei, who saw his agency vaulted into prominence during a high-profile 12-year tenure. Developing countries supported Amano's rival, South Africa's Abdul Samad Minty, considered ready to challenge the US and other nuclear power countries on issues such as disarmament - and which are generally supportive of Iran's claims to having a right to nuclear power. An initial session in March ended inconclusively and Thursday's meeting went down to the wire, with Amano winning only in the fourth round. That and the fact that Amano barely eked out his victory, just clearing the two-thirds majority needed, reflected a continuing divide between the two camps. The divisions have served as an obstacle in one of its key tasks - probing nations suspected of secret, possibly weapons-related, nuclear activities. While Amano was born after the US nuclear strikes that ravaged Hiroshima and Nagasaki in 1945, he alluded to those events in brief comments to reporters, suggesting that as a "national coming from Japan" he would work particularly hard to reduce the threat from atomic arms. Expanding on that theme in recent comments to the Austrian daily Die Presse, he said that he was "resolute in opposing the spread of nuclear arms because I am from a country that experienced Hiroshima and Nagasaki." Now his country's chief delegate to the IAEA, Amano was previously his country's senior official for disarmament and related issues. He has also chaired key IAEA meetings during his more than three-year tenure as chief IAEA delegate. He still needs to be confirmed by the board, in a session planned for Friday, and in September by the full IAEA general assembly. IAEA officials suggested both meetings would rubber-stamp the choice of Amano, saying it would be unheard of for them to overturn Thursday's vote results. Amano collected 23 votes, to 11 for Minty - just giving him the two-thirds majority needed for victory. Amano touched on the North-South divide gripping the agency in his post-session comments. Saying he would do his utmost to prevent nuclear proliferation, Amano, 62, appealed for "solidarity of all the member states - countries from North, from South, from East and West" to achieve that goal. Amano will be taking control of the IAEA at a particularly difficult time. Its nuclear investigations of Iran and Syria are both deadlocked, and it has no overview at all of North Korea, which is forging ahead with its nuclear arms program. The Iranian investigation in particular has been affected by the deep divide between Western nations, including the United States, and developing countries that accuse the West of being indifferent to the problems of poorer countries. Iran is under three sets of UN Security Council sanctions for refusing to freeze its uranium enrichment program - an activity that Teheran insists is meant to generate nuclear fuel but which can also be used to produce fissile material for nuclear warheads. Representatives of some developing nations have privately said they share Western fears that Iran may seek to use enrichment to develop weapons. But as a bloc, they tend to support Iran's argument that it has a right to an enrichment program for generating energy. The developing bloc also questions the West's assertions that Iran in the past ran experiments and drew up plans reflecting its interest in nuclear weapons, backing Teheran's dismissal of US and other intelligence pointing to such activities. ElBaradei steps down in November and the US and its backers had backed Amano as a man sympathetic to their focus - nonproliferation. Minty, in contrast, was generally seen as ready to give more weight to demands by the developing countries pushing the US and other nuclear weapons states to disarm. John Bolton, the US ambassador to the United Nations under the previous administration, hailed Amano's victory in comments indirectly critical of Elbaradei. "I think he will reduce the politicization of the IAEA," he said. "That alone will bring back things into equilibrium."