Joe Biden expects Iran to attack Israel 'sooner rather than later'

US President Joe Biden on Friday said he expected Iran to attack Israel "sooner, rather than later" and warned Tehran not to proceed.

Asked by reporters about his message to Iran, Biden said simply, "Don't", and he underscored Washington's commitment to defend Israel.

"We are devoted to the defence of Israel. We will support Israel," the President said. "We will help defend Israel and Iran will not succeed."

Biden said he would not divulge secure information but added his expectation was an attack could come "sooner, rather than later".

Earlier, White House spokesperson John Kirby said the reportedly imminent attack by Iran on Israel was a real and viable threat but gave no details about any possible timing.

Kirby said the US was looking at its own force posture in the region in light of Tehran's threat and was watching the situation very closely.