US and Israeli officials committed to coordinating efforts to prevent Iran from acquiring nuclear weapons in a meeting of senior officials, the White House said in a statement on Wednesday.
The officials also discussed economic and diplomatic steps to achieve their goals and reviewed ongoing cooperation between the US and Israeli militaries in Tuesday's meeting, the White House said.
Iran warned Wednesday it would respond to any "unconstructive actions" taken by the UN atomic watchdog after the agency reported traces of nuclear material at undeclared sites in Iran.
Iran and the UN agency agreed in March on an approach to resolve the issue of the nuclear material found at Marivan, Varamin and Turquzabad -- sites that had not been declared by Iran as having hosted nuclear activities.
But in a report on Monday the International Atomic Energy Agency said it still had questions which were "not clarified" despite long-running efforts to get Iran to explain the presence of the nuclear material.
The IAEA board of governors is to hold a meeting on Monday for which Britain, France, Germany and the US have prepared a draft resolution "calling on Iran to cooperate on the question of undeclared sites", according to a European diplomatic source.
"We will respond firmly and appropriately to any unconstructive action at the board of governors," Iranian foreign ministry spokesman Saeed Khatibzadeh said in a statement.