United States President Donald Trump said the American military operation dubbed "Epic Fury" is projected to last four to five weeks, with the possibility of extending further if necessary.

The operation aims to halt the development of Iran's nuclear and ballistic missile programs and dismantle its capabilities, which the US considers a threat to its security and that of its allies.

Trump said his administration had planned for this timeline from the start. 

"Whatever it takes — we projected four to five weeks, but we have the capability to go far longer than that," he said.

The US president described the strikes as a long-planned strategic decision, calling it the last window to act against the Iranian regime. 

"This was our last best chance to strike and eliminate the intolerable threats posed by this sick and sinister regime," Trump said.

He outlined the key objectives of the operation, which include destroying Iran's missile capabilities, cutting off its support for militant groups, and ensuring it cannot develop a nuclear weapon. 

"Our objectives are clear. First, we're destroying Iran's missile capabilities," he said.

Trump also acknowledged that American service personnel have been killed in the course of the operation. Despite this, he said the United States is resolved to press on. 

"In their memory, we continue this mission with ferocious, unyielding resolve to crush the threat this terrorist regime poses to the American people," the US president said.