The US Central Command posted a picture of the submarine the day before on social media platform X that appeared to show it transiting Egypt's Suez Canal.

It is "now in the Fifth Fleet area of operations," Pentagon spokesman Brigadier General Pat Ryder told journalists, referring to an area that includes the Gulf, Red Sea and parts of the Indian Ocean.

"What this does... is further support our deterrence efforts in the region," he said, without providing further details.

Some Ohio-class submarines are armed with nuclear-tipped ballistic missiles, while others are configured to carry more than 150 Tomahawk cruise missiles.

Ryder did not specify which type is currently in the Middle East, but cruise missiles would have more immediate utility in the event of an escalation of the Israel-Hamas conflict that began earlier this month when the militant group killed 1,400 people in a cross-border attack from Gaza.

Israel's military responded to the October 7 attack with a withering air, land and naval assault on Gaza that the territory's health ministry said Monday has left more than 10,000 people dead.

The United States has bolstered its forces in the region in a bid to keep the conflict from spreading into a broader war, deploying two carrier strike groups and other assets to drive home its message that regional actors should not seek to take advantage of the unrest.

US forces in Iraq and Syria have faced a spike in attacks since mid-October that Washington has blamed on Iran-backed forces, carrying out strikes last month on sites in Syria the Pentagon said were tied to Tehran.