U.S. and Israeli officials have warned Iran that it will not be allowed to acquire a nuclear weapon.
In Jerusalem, U.S. Secretary John Kerry said negotiations with world powers over Tehran's nuclear program cannot be open-ended.
"Iran cannot have and will not have a nuclear weapon, and the United States of America has made clear that we stand not just with Israel but with the entire international community in making it clear that we are serious," Kerry said. "We are open to negotiation, but it is not an open-ended, endless negotiation. It cannot be used as an excuse for other efforts to try to break out with respect to a nuclear weapon."
He made the statement at joint news conference after meeting with Israeli Prime Minister Benjamin Netanyahu.
The Israeli leader said Iran's alleged bid for nuclear weapons must be stopped.
"I think we also understand what it means for the world to have rogue states with nuclear weapons," Netanyahu said. "Iran cannot be allowed to cross into that world, it cannot be allowed to continue its nuclear weapons program, and we must not allow it to continue to do so in defiance of the entire international community."
Some governments fear Iran is enriching uranium in order to manufacture atomic weapons, and the UN watchdog, the International Atomic Energy Agency (IAEA), has accused Tehran of conducting a covert nuclear arms program.
But Iran says its nuclear program is for energy and medical purposes and staunchly defends its right to produced highly enriched uranium.
Both Kerry and Netanyahu pledged new efforts to revive the Israeli-Palestinian peace process, which has been dormant since September 2010.
The top U.S. diplomat is on his second trip to Israel and the Palestinian territories in as many weeks.
The caution to Iran comes after two days of international talks in Kazakhstan aimed at limiting Iran’s nuclear program ended on April 6 with no notable progress.
Iran’s state news agency this week said the country has opened two new uranium mines
and a new uranium-production facility.
Based on reporting by dpa, AFP, and Reuters