US Secretary of State Mike Pompeo criticised European countries for not being "helpful" over the decision to launch an armed drone strike that killed prominent Iranian general Qassem Soleimani.

"The Brits, the French, the Germans all need to understand that what we did, what the Americans did, saved lives in Europe as well... This was a good thing for the entire world," he told Fox News host Sean Hannity.

The targeting of Soleimani, the head of Iran's elite Quds Force, was arguably the most provocative US military action in the Middle East since President George W. Bush launched the 2003 Iraq war to topple Saddam Hussein.

The killing came as President Donald Trump sought to apply increased pressure on Iran through economic sanctions to abandon its nuclear weapons programme, while Tehran countered with provocative attacks on US military and oil facilities in the region.

By taking out Soleimani, Trump signalled to Iran that his patience has worn thin.

"We caught him and we stopped him," Pompeo said. "It's a good thing for the world."

He said Soleimani and his militant allies were planning an attack "at some scale."

"We can't talk much about the details, but suffice it to say, the American people can know that the decision that President Trump made to take Qassem Soleimani down saved American lives," he said.

"But I spent the last day and a half, two days, talking to partners in the region, sharing with them what we're doing, why we're doing it, seeking their assistance, they've all been fantastic. And then talking to our partners in other places that haven't been quite as good. Frankly, the Europeans haven't been as helpful as I wish that they could be."