Over 50,000 troops, 200 fighter jets and two aircraft carriers are taking part in joint US-Israeli attacks on Iran, US Central Command (CENTCOM) Commander Gen. Brad Cooper said Tuesday.

In a video message, Cooper said the operation—now in its fourth day—represents the largest US military buildup in the Middle East in a generation.

He said US and Israeli forces have struck nearly 2,000 targets across Iran using more than 2,000 munitions since the campaign began.

Iran has responded with large-scale retaliatory attacks, launching more than 500 ballistic missiles and over 2,000 drones, according to Cooper.

"We are also sinking the Iranian Navy, the entire navy. Thus far, we've destroyed 17 Iranian ships," he said.

Despite the retaliation, Cooper said Iran’s ability to strike US forces and allies is declining as the campaign continues.

Tensions have escalated across the region since the US and Israel launched large-scale attacks on Iran on Saturday, killing nearly 800 people, including Supreme Leader Ayatollah Ali Khamenei and top military officials.

Iran has responded with drone and missile strikes targeting Israel as well as Gulf countries, which are home to US military assets.

Six US service members were killed and several others wounded in an Iranian strike on a tactical operations center in Kuwait during the operation, CENTCOM announced. (AA)