The Biden administration is gearing up for a potential retaliation campaign against Iran after US troops were killed by Iran-backed militia on Sunday.

According to US officials speaking to NBC News, specific targets for retaliation have not yet been finalized, but Iranian interests beyond Iran's borders are under consideration. It could last for several weeks, they said.

The decision to retaliate comes after Iran-backed militants killed three US service members at a base in Jordan on Sunday, in addition to more than 160 attacks on US targets in the Middle East since the onset of the Gaza war in October. Iran-back militia have targeted the US for its support of Israel and its right to defence following the October 7 invasion by Iran-backed Hamas, which saw over 1,200 people murdered and 250 at least taken hostage.

The planned offensive is “expected to include Iranian targets outside Iran, and the campaign will involve both strikes and cyber operations,” added the officials.

President Biden stated on Tuesday that he had decided on the country's response to the proxy drone attack but refrained from disclosing further details. On Monday, US Secretary of State Antony Blinken also emphasized that the country's approach to responding to the attack would be "multi-tiered."

In Tehran, the government reiterated it would not tolerate attacks on its territory. State media quoted Iran's foreign minister, Hossein Amir-Abdollahian, as telling a cabinet meeting: "The US has to stop its threats and focus on a political solution."

Iran's United Nations envoy Amir Saeid Iravani, also said on Wednesday that Tehran would respond "decisively" to any attack on its territory, its interests, or Iranian nationals outside its borders, as reported by Reuters.