Europe's top diplomat Federica Mogherini warned Tuesday that the mounting tension between Saudi Arabia, Iran and their respective allies and proxies is "extremely dangerous," Daily Mail reported.

Speaking in Washington, Mogherini stopped short of criticizing US President Donald Trump's warm support for Saudi crown prince Mohammed bin Salman's aggressive anti-Iranian stance.

But she made it clear that in Europe, in any case, officials would like to see both sides calm their rhetoric and seek a "minimum of common ground" on which to build peace.

"I know that this is not the wind that is blowing as the majority voice in the world of today," Mogherini told reporters at the EU mission in Washington.

"But allow me to bring a little bit of wisdom as the European voice in a world that seems to go completely crazy here: It's dangerous." she warned.

Mogherini was cautious on the Saudi crackdown and mass arrests, saying that Europe would support any moves to fight corruption and modernize the kingdom's economy.

But she would not comment on Trump's enthusiastic tweeted support for Prince Salman, including his "harshly treating" figures who had been "milking" their country.

Instead, she noted that the European Union and Canada were among "very few" governments that can claim human rights and the rule of law are central to their foreign policy.

"Here, I know, the thinking has gone in a different direction," she added, in an implicit reference to Trump's "America First" approach to world issues.