Israel has not yet decided to carry out a pre-emptive military strike against Iran\'s nuclear program and Tehran appears reluctant to provoke a conflict, the head of the US Defense Intelligence Agency told lawmakers Thursday. The assessment from Lieutenant General Ronald Burgess reinforced comments by President Barack Obama and other top officials who have played down the possibility of an imminent Israeli attack on Iran, amid intense speculation Israeli leaders are poised to stage bombing raids to prevent Tehran from obtaining nuclear weapons. \"To the best of our knowledge, Israel has not decided to attack Iran,\" Burgess told the Senate Armed Services Committee. Iran was working to bolster its naval and ballistic missile capabilities, could launch missile attacks against the West if attacked, \"temporarily\" shut the strategic Strait of Hormuz and could deploy \"terrorist surrogates\" abroad in the case of a war, Burgess said. \"However, the agency assesses Iran is unlikely to initiate or intentionally provoke a conflict,\" he said. Iranian leaders have yet to take a decision to build a nuclear weapon but are expanding the country\'s technical capacity in the meantime, said James Clapper, director of national intelligence. \"We believe the decision would be made by the supreme leader himself and he would base that on a cost-benefit analysis,\" Clapper said. He said that Iran\'s supreme leader Ali Khamenei likely did not want a nuclear weapon \"at any price\" and that demonstrated \"the value of sanctions\" imposed by the United States and other countries against Tehran. Israeli Prime Minister Benjamin Netanyahu on Thursday said sanctions against Tehran \"haven\'t worked\" while Iran on Wednesday announced it had installed another 3,000 centrifuges to increase its uranium enrichment abilities while stepping up exploration and processing of uranium yellowcake. Iran faces four sets of UN sanctions and a raft of unilateral US and EU sanctions designed to halt a program the West fears masks a drive for nuclear weapons. Tehran denies this charge, saying its nuclear project is entirely peaceful.