US Defense Secretary Lloyd Austin has ordered the deployment of a guided missile submarine to the Middle East, the Pentagon said on Sunday, as the region braces for possible attacks by Iran and its allies after the killing of senior members of Hamas and Hezbollah.

While the USS Georgia, a nuclear-powered submarine, was already in the Mediterranean Sea in July, according to a US military post on social media, it was a rare move to announce the deployment of a submarine publicly.

After Austin spoke with his Israeli counterpart, the Pentagon said Austin had ordered the Abraham Lincoln strike group to accelerate its deployment to the region.

"Secretary Austin reiterated the United States' commitment to take every possible step to defend Israel and noted the strengthening of US military force posture and capabilities throughout the Middle East in light of escalating regional tensions," the statement added.

The US military had already said it will deploy additional fighter jets and Navy warships to the Middle East as Washington seeks to bolster Israeli defenses.