US President Joe Biden has said he does not support any potential Israeli retaliatory strike on Iranian nuclear sites after Iran launched around 180 missiles at Israel.

Tensions are high between Iran and Israel after the Iranian attack on Tuesday, which Israel said was mostly repelled by its missile defence system.

Iran said the barrage was a response to the killings of Hamas political leader Ismail Haniyeh, Hezbollah leader Hassan Nasrallah and Iranian Revolutionary Guards Corps commander Brig-Gen Abbas Nilforoushan.

Its attack also came after Israel announced a ground assault into Lebanon, in an effort to dismantle what it called Iran-backed Hezbollah's “terrorist infrastructure” in border villages.

The US has repeatedly called for de-escalation and has also led long-running negotiations on a ceasefire between Israel and the Palestinian armed group Hamas in Gaza but so far without success.

Biden's comment to reporters on Wednesday came during a trip to tour hurricane damage in North Carolina with Vice President Kamala Harris.

"Would you support an attack on Iran's nuclear sites by Israel?" Biden was asked by a reporter.

"The answer is no," he responded.

He added that the US "will be discussing with the Israelis what they're gonna do".

He also said that he had consulted with the leaders of other G7 countries and they all agreed that Israel "has the right to respond, but they should respond proportionally".

US State Department spokesman Matthew Miller, at a briefing, added: “It’s clear that this was an unprecedented escalation by Iran.

"Israel has the right to respond to it. We’re having discussions about what that response will be”.

So far, the White House has given no public indication of how it believes Israel should respond to Iran's attack.

In a video message on Tuesday, Biden said that at his direction, US military forces in the region had helped shoot down the missiles fired from Iran.

He said the Iranian attack had been "defeated and ineffective", calling it "a testament to intensive planning between the United States and Israel to anticipate and defend against the brazen attack we expected."

"Make no mistake, the United States is fully, fully, fully supportive of Israel," Biden added.