President Donald Trump vetoed an Israeli plan in recent days to kill Iran's Supreme Leader Ali Khamenei, two US officials told Reuters on Sunday.

"Have the Iranians killed an American yet? No. Until they do, we're not even talking about going after the political leadership," said one of the sources, a senior US administration official.

The officials, speaking on condition of anonymity, said top US officials have been in constant communications with Israeli officials in the days since Israel launched a massive attack on Iran in a bid to halt its nuclear program.

They said the Israelis reported that they had an opportunity to kill the top Iranian leader, but Trump waved them off of the plan.

The officials would not say whether Trump himself delivered the message. But Trump has been in frequent communications with Israeli Prime Minister Benjamin Netanyahu.

When asked about Reuters report, Netanyahu, in an interview on Sunday with Fox News Channel's "Special Report With Bret Baier," said: "There's so many false reports of conversations that never happened, and I'm not going to get into that."

"But I can tell you, I think that we do what we need to do, we'll do what we need to do. And I think the United States knows what is good for the United States," Netanyahu said.

Trump has been holding out hope for a resumption of US-Iranian negotiations over Tehran's nuclear program. Talks that had been scheduled for Sunday in Oman were canceled as a result of the strikes.

Trump told Reuters on Friday that "we knew everything" about the Israeli strikes.