Tehran, Iran - Iran said Monday it "will not hesitate" to respond in the event of US attacks on its territory after the White House declined to say whether strikes on the country were ruled out.

White House National Security Advisor Jake Sullivan said Sunday the US will press on with its retaliation against groups in Iraq and Syria.

Asked whether the United States would rule out the possibility of striking Iran directly, Sullivan told NBC, "it would not be wise for me to talk about what we're ruling in and ruling out."

"If (Iran) chose to respond directly to the United States, they would be met with a swift and forceful response from us," he said.

Iran's foreign ministry spokesperson Nasser Kanani hit back on Monday, saying: "The Islamic Republic has shown that it has always reacted decisively to any threat to its security, territorial integrity and sovereignty."

Iran "will not hesitate to use its capabilities" to respond to any attacks on its soil, said Kanani during his weekly press briefing.

He nonetheless reiterated that Iran "does not seek to aggravate tensions and crises in the region."

Regional tensions have soared since the October 7 outbreak of the Israel's war on Gaza, drawing in groups in Iraq, Syria, Yemen, and Lebanon.

The US military said it carried out airstrikes against five missiles in Yemen on Sunday.

The strikes came a day after US and UK forces launched a wave of air raids against Yemen's Houthis – their third round of joint military action in response to persistent attacks on commercial shipping.

The Houthis say their actions in the Red Sea are in solidarity with Palestinians in Gaza, at least 27,365 of whom have been killed in Israel's ongoing military assault.

The US military struck targets in Syria and Iraq overnight on Friday to Saturday, in retaliation for a January 28 drone attack on a base in Jordan that killed three US soldiers.

The Islamic republic condemned the strikes in Yemen, Syria, and Iraq.

President Joe Biden has blamed "radical Iran-backed militant groups" for the attack in Jordan, but said the United States does not seek a wider conflict in the Middle East.

Many American peace activists have called on Biden to stop funding Israel's military campaign in Gaza and to remove US troops from the Middle East.