US officials have said that the anticipated Iranian attack on Israel could occur in the coming days, with the country watching the region closely for any indication of how it might play out.

It could be similar to the barrage of ballistic missiles and drones which Iran launched against Israel in April. However, there are fears that it could be larger and more complex.

Hezbollah leader Hassan Nasrallah hinted that a coordinated attack on Israel could be in the works after Israel assassinated one of the Iran-backed group’s top commanders in Beirut, Fuad Shukr, head of the group's military operations, less than 24 hours before the killing of Ismail Haniyeh in Tehran. An Iranian military adviser and five civilians were also killed in the former attack.

“Because they have picked a fight with everyone, they don’t know where the response will come from … the response will come separately or coordinated,” he said in a speech on Thursday.

Haniyeh, alongside his personal bodyguard, was assassinated on July 31 after having returned to his accommodation in a military-run guesthouse , following his attendance of the inauguration ceremony for Iranian president Masoud Pezeshkian. Reports differ on the method of killing, ranging from a missile strike to a remotely detonated explosive device hidden in his bedroom. The investigation has led to the arrest of over two dozen individuals, including senior intelligence and military officials, as well as the guesthouse staff.

The funeral for the Hamas political leader was held on Friday, as mosques across several countries also hosted commemoration ceremonies. The day before, a large procession led by Iran’s Supreme Leader Ali Khamenei, drew thousands. Haniyeh is expected to be buried later in Lusail, Hamas said.

The US is sending a carrier strike group, a fighter squadron and additional warships to the Middle East. This could become the largest movement of US forces in the region since the early days of the Gaza war, when the Pentagon sent two carrier strike groups toward the Middle East in a public warning to regional militant groups to not amplify the fighting, according to CNN World.

Defense Secretary Lloyd Austin order the USS Abraham Lincoln strike group to replace the USS Theodore Roosevelt strike group, currently operating in the Gulf of Oman, according to a statement from deputy Pentagon press secretary, Sabrina Singh.

Destroyers and cruisers capable of ballistic missile defence will also be sent to the Middle East and the Mediterranean Sea.

The US already has the USS Wasp amphibious assault ship in the region, which operates with the 24th Marine Expeditionary Unit, capable of carrying out an evacuation of US citizens in Lebanon if required.

Israel has not commented on the killing, according to CNN.