The United States is sending a third aircraft carrier strike group toward the Middle East as the war with Iran enters its eighth month.

A US official told Al Jazeera that the USS Theodore Roosevelt left its base in San Diego on Sunday, bound for the Central Command area of operations which covers the Middle East. It was followed a day later by the USS Makin Island Amphibious Ready Group carrying more than 2,000 Marines from the 13th Marine Expeditionary Unit.

The deployment will add 9,000 to 10,000 more troops to the region and is expected to arrive by the end of November. Once in theatre, the Roosevelt will join the USS George H.W. Bush and USS George Washington which are already operating in the region.

If all three remain on station, it will be the first time since April that three US carrier strike groups have been deployed to the Middle East, before a fragile ceasefire between the US and Iran collapsed. The additional personnel will join more than 50,000 US troops already in the region.

The buildup comes as President Donald Trump weighs ramping up military action against Iran. Trump told the UN General Assembly last week that he was facing a choice over whether to pursue a deal or drive Iran “into hell”.

US officials said the deployment gives Trump additional military options if he decides to intensify operations, including F-35s and Marines. Defense Secretary Pete Hegseth has said American forces are “ready to go” if ordered to strike.