US spy chief, James Clapper said Monday that strict monitoring of Iran remains a key focus of the US intelligence community and the International Atomic Energy Agency (IAEA)."We need the basic foundational information and insight provided by those inspections and surveillance capabilities represented by the IAEA, which then we would double check, verify with our own organic intelligence capabilities and that of our partners, and notably, the Israelis," the US national intelligence director told Charlie Rose "My focus and the focus of the intelligence community is our ability to verify if negotiations are successful and there are some agreements struck, is our ability to monitor and verify that" Clapper said.His remarks come as the US has quietly cautioned Israel not to undercut Iran nuclear negotiations that resumed on Monday as Prime Minister Benjamin Netanyahu prepared to make the case against his diplomacy before the US Congress.Netanyahu says he fears US President Barack Obama's Iran diplomacy could allow Israel's arch Middle East adversary to develop atomic weapons. US officials say the best way to prevent that outcome is a negotiated settlement.Washington and some allies, notably Israel, suspect Iran has used its civilian nuclear program as a cover to develop a nuclear weapons capability. Iran denies this, saying its program is for peaceful purposes such as generating electricity.US Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif met on the first of what could be three days of talks in the Swiss lakeside town of Montreux on curbing Iran's nuclear program in exchange for relief from economic sanctions.The two men, along with US Energy Secretary Ernest Moniz and Iranian atomic energy chief Ali Akbar Salehi, shook hands and then met for about 50 minutes on Monday afternoon, followed by a second session of about 40 minutes.One of the disputes holding up a final agreement is over the pace at which sanctions should be dismantled. Tehran wants them rapidly removed while Western powers want gradual steps responding to Iranian performance in implementing the accord.