Joe Biden has warned Iran that the US will 'act forcefully' to protect Americans, after the US military carried out airstrikes against Iran-backed forces in retaliation for an attack in Syria.

'Make no mistake: the United States does not ... seek conflict with Iran, but be prepared for us to act forcefully to protect our people,' Biden told reporters during a visit to Canada.

Officials said a US service member was wounded in Syria on Friday in the latest tit-for-tat strike between Iran-backed forces and US personnel

Syria attacks: Biden warns Iran US will ‘act forcefully’ to protect Americans