The US military has launched retaliatory air strikes against Iranian forces and Tehran-backed militia groups in Iraq and Syria, killing at least 18 fighters, following a deadly drone attack on an American base in Jordan, AFP reports.

The strikes targeted the Islamic Revolutionary Guard Corps Quds Force as well as “affiliated militia groups,” with American forces including long-range bombers flown from the United States hitting “more than 85 targets,” the US Central Command (Centcom) said in a statement.

“The airstrikes employed more than 125 precision munitions,” Centcom said. Targets included command and control and intelligence centres as well as rocket, missile and drone storage facilities belonging to militia groups and Iranian forces “who facilitated attacks against US and coalition forces.”

The strikes killed at least 18 pro-Iran fighters, according to the Syrian Observatory for Human Rights war monitor.

“Our response began today. It will continue at times and places of our choosing,” President Joe Biden said in a statement.

“The United States does not seek conflict in the Middle East or anywhere else in the world. But let all those who might seek to do us harm know this: If you harm an American, we will respond,” he added.