The US is dispatching roughly 9,000 sailors and Marines aboard a flotilla of warships to the Middle East, a major naval buildup that could bring three American aircraft carriers to the region by late October or November as President Donald Trump warns that renewed strikes against Iran remain possible.

The move, confirmed by US officials who spoke on the condition of anonymity to discuss sensitive military operations and reported by major US media outlets, marks one of the largest concentrations of US naval power in the Gulf and Arabian Sea since the 2003 invasion of Iraq.

It comes as diplomatic efforts to end the eight-month-old US-Iran conflict have stalled, with Tehran and Washington trading accusations and threats even as both sides say they seek to avoid an all-out regional war.