Iran could hit U.S. bases in the Middle East in response to any Israeli strike on its nuclear facilities even if American forces played no role in the attack, the leader of Lebanon's Iranian-backed militant group Hezbollah said, according to Reuters.

"A decision has been taken to respond and the response will be very great," Hezbollah Secretary-General Sayyed Hassan Nasrallah said in an interview with the Beirut-based Al Mayadeen television.

"The response will not be just inside the Israeli entity - American bases in the whole region could be Iranian targets," he said, citing information he said was from Iranian officials. "If Israel targets Iran, America bears responsibility."

Israel had several "weak points" which could be targeted, including "economic, industrial, electrical, chemical and nuclear" sites, the Hezbollah leader said.

Even if Israel launched a first strike attack on Lebanon, destroying a large part of Hezbollah's missile arsenal, the militant group would retain the capacity to hit back with deadly force, he added.

Two weeks ago Nasrallah said Hezbollah could kill tens of thousands of Israelis by hitting targets with what he described as precision-guided missiles. "Hitting these targets with a small number of rockets will turn ... the lives of hundreds of thousands of Zionists to real hell," he said at the time.