Iranian leaders have decided to respond to last week's Israeli attack, but the nature and timing remain unclear amid conflicting reports.

Iran is planning a counterattack on Israel involving more powerful warheads and other weapons, the Wall Street Journal reported, citing Iranian and Arab officials briefed on the plans.

Amid U.S. warnings against a counterattack on Israel, Iran is sending a defiant diplomatic message: It is planning a complex response involving even more powerful warheads and other weapons, said Iranian and Arab officials briefed on the plans.