Israel has asked the United States for a bomb capable of attacking Iran's underground nuclear sites, an Israeli official told Reuters.
Israeli Prime Minister Benjamin Netanyahu requested the "bunker-buster" bomb during his visit to Washington this week.
Some analysts suggest the U.S. might agree to give Israel the weapon but only if it promises not to attack the Islamic Republic this year.
The report comes amid growing tension between the Jewish state and the U.S. over how to address the growing nuclear threat from Iran.
In an address to Washington, D.C.'s American Israel Public Affairs Committee conference this week, Netanyahu made it clear it would chart its own course when it comes to engaging Tehran.
"My friends, we deeply appreciate the great alliance between our two countries," the prime minister said. "But when it comes to Israel's survival we must always remain the masters of our fate."
Meanwhile, White House officials have denied the report, saying no such agreement was proposed or reached.