US President Donald Trump said in an interview with NBC News that US strikes are proceeding "ahead of schedule" and suggested that one possible outcome of the attacks is the "decapitation" of Iran's leadership.

"We expect casualties from something like this. We have three, but we expect losses, but ultimately it will be very important for the whole world," Trump said, referring to three American soldiers killed in Kuwait during the operation.

When asked what outcome he would like to see, Trump described possible scenarios.

"There are many good outcomes," he said. "One, decapitate them, get rid of a whole group of murderers and thugs. And there are many, many outcomes. We could do the short version or the longer version."

The US president also said Iranian officials are interested in continuing negotiations with the US, but refused to say whether the US would pause strikes during diplomatic efforts.

"I don't know if they'll be able to satisfy us. They weren't able to," he said.

Trump again stated that he launched the strikes because the Iranians "were not willing to stop their nuclear research" and "were not willing to say they won't have nuclear weapons."