US Defence Secretary Pete Hegseth earlier announced the "deployment of additional capabilities" to the Middle East to enhance the Pentagon's "defensive posture", despite US officials' denial at the time that they were joining the military action.

At least 30 US military planes have been moved from bases in America to Europe over the past three days, flight tracking data reviewed by BBC Verify has shown.

It was unclear whether the US movements were directly connected to the Israel-Iran conflict, but one expert said the tanker aircraft flights were "highly unusual".

Another expert said that the movements could be part of a broader policy of "strategic ambiguity" aimed at influencing Iran to make concessions.

Signing up to Israeli military action does not have full agreement from Trump's closest advisers, CBS reported. But the dissenting voices have not gone public.

There are also a wide range of views within Trump's supporter base. The Republican ran for re-election on the basis that he would disentangle America from conflicts overseas, and he has previously criticised US intervention in the Middle East.

On the question of Iran's capacity to build a nuclear weapon, there appears to be a differing assessment by Trump and his director of national intelligence, Tulsi Gabbard.

Asked on Tuesday about Gabbard's earlier suggestion that Iran was not working on a nuclear warhead, Trump replied: "I don't care what she said. I think they were very close to having one."

Advisers to both Trump and Gabbard later denied the pair disagreed on the issue.

There were no deaths overnight from Tuesday into Wednesday in Israel from Iranian missile attacks.

And more than 50 Israeli fighter jets conducted operations in Iran overnight, with strikes on an Iranian centrifuge facility, a missile production facility near Tehran, and a university linked to Iran's Revolutionary Guards.

Israel is America's main partner in the Middle East, and Trump has continued to stand by Israeli Prime Minister Benjamin Netanyahu amid widespread international condemnation of Israel's military actions in Gaza following the Hamas attacks on Israel on 7 October 2023.