US soldiers patrol an area in the town of Tal Hamis, southeast of the city of Qameshli in Syria's northeastern Hasakeh governorate, on Jan 24, 2024. (PHOTO / AFP)

WASHINGTON — The United States will launch more strikes against Iran-backed militia groups in the Middle East, the top US national security official said Sunday, refusing to rule out the possibility of hitting targets inside Iran.

"We intend to take additional strikes and additional action to continue to send a clear message that the United States will respond when our forces are attacked, or people are killed," US National Security Advisor Jake Sullivan told NBC's "Meet the Press" host Kristen Welker.

Coalition forces of the United States and Britain launched strikes from both air and surface platforms against three dozens of targets spreading across 13 locations in Houthi-controlled areas in Yemen

Sullivan, who appeared on multiple Sunday morning shows to discuss the current US administration's military response in the Middle East following a deadly attack on US forces, did not rule out launching US military action across the border of Iran.

READ MORE: Iran, Hamas condemn latest US-UK strikes on Yemen's Houthis

"I would just say, from the perspective of Tehran, if they chose to respond directly to the United States, they would be met with a swift and forceful response from us," said Sullivan when asked by George Stephanopoulos, host of ABC's "This Week."

The remarks came against the backdrop of the United States launching retaliatory strikes Friday against targets used by Iran's Islamic Revolutionary Guard Corps and its affiliated militant groups in Iraq and Syria.

The Biden administration said the US strikes were the first round of what would be a multi-tier response to a deadly attack on Jan 27, in which three US soldiers were killed in Jordan by what the United States said was an Iranian-manufactured drone launched by militias receiving support from Tehran.

On Saturday, coalition forces of the United States and Britain launched strikes from both air and surface platforms against three dozens of targets spreading across 13 locations in Houthi-controlled areas in Yemen.

READ MORE: US starts retaliatory strikes on Iran-linked targets in Iraq, Syria

Though claiming that the Houthis are also backed by Iran, the Pentagon tried to differentiate Saturday's strikes from those conducted on Friday, saying the ones targeting the Houthis were aimed at deterring the group from further attacking international shipping.