"The US thanks our close friends, UK, France, and Germany, for their clear articulation of Iran's sole responsibility for the act of war against Saudi Arabia and its impact on the region and the world," Pompeo wrote on Twitter.

"This will strengthen diplomacy and the cause of peace. We urge every nation to join in this condemnation of Iran's actions."

France, Germany and Britain released a joint statement on Monday saying that Iran "bears responsibility" for the attack on a Saudi Arabian oil plant this month which drastically hurt Riyadh's production capacity.

"It is clear to us that Iran bears responsibility for this attack. There is no other plausible explanation. We support ongoing investigations to establish further details," the three European nations said in a joint statement.

French President Emmanuel Macron, British Prime Minister Boris Johnson and German Chancellor Angela Merkel have met during the annual United Nations gathering of world leaders to co-ordinate their strategy on Iran as the European parties seek to save a 2015 nuclear deal and defuse tensions between Washington and Tehran.

Iran has denied involvement in the oil plant strike on September 14, which was claimed by Iranian-backed Houthi rebels in Yemen, but the United States has doubted that narrative.

US Secretary of State Mike Pompeo directly blames Iran; President Donald Trump has been less specific while still generally pointing the finger at Tehran.

Trump has resisted calls by US hawks to take military action against Iran, saying restraint shows strength.

The leaders of France, Germany and Britain stressed their "continued commitment" to the 2015 multi-national nuclear deal with Iran, urging the country to "adhere fully to its commitments under it".

The US pulled out of the 2015 deal, known as the JCPOA, and is reimposing tough sanctions on Iran, notably on its central bank, financial sector and its vital oil sector.

Iranian Foreign Minister Javad Zarif reacted to the statement by the three European nations by saying they were parroting Washington's rhetoric against Iran.

"No new deal before compliance [with the] current one," Zarif posted on Twitter from New York. Europe, he said, needed "to forge [an] independent path".

British Prime Minister Boris Johnson went beyond the joint statement and issued a call for a new nuclear agreement with Iran, saying he hopes Trump negotiates a fresh deal.

"Let's do a better deal," Johnson said in an interview with US broadcaster NBC, referring to the previous agreement as a "bad deal" echoing language from Trump.

The European statement comes as world leaders are gathering for the UN General Assembly in New York.

Trump is due to address the assembly on Tuesday, while Iranian President Hassan Rowhani is scheduled to speak on Wednesday.

Australian Associated Press