British Prime Minister Boris Johnson announced on September 23, the UK might take part in coordinated military action in the middle east if the US asks to do so. The statement came with regard to the formal identification of Iran as the perpetrator behind the drone and missile strikes on Saudi Arabia's Aramco plant on September 14. Johnson gave the aforementioned information at New York where he will be attending the UN General Assembly. The Prime Minister was quoted saying the UK wanted to de-escalate tensions but did not rule out the probability of taking military action.
Read: Aramco Attacks Show Company Entanglement In Saudi Arabian Politics

Saudi Arabia, US& UK blame Iran for Aramco attacks

Three countries- UK, US and Saudi Arabia- collectively blame Iran for the attack on Aramco plants. The earlier claim by Houthi rebels possibly attacking Aramco has been dismissed. However, Tehran continues denying any involvement. The Khurais oil field and Abqaiq oil processing facility in eastern Saudi Arabia which is a key part of the country's oil production infrastructure was crippled after the drone and cruise missile attacks. About 50% of oil production was affected. 

Earlier Mike Pompey, the US Secretary of State, had called the attacks an act of war. On the other hand, on the sidelines of the UN event, Johnson plans to meet Iranian President Rouhani and US President. He made it clear that he would provide all assistance for solving the issue. He said that everyone ones to do what they can to bring the world together in response to what happened in Saudi Arabia in our management of Iran. Johnson reiterated the UK and Saudi Arabia's blame on Iran for the strikes saying that the current difficulty is organizing a global response to it. He added that the UK, US, and other European countries will work together to de-escalate tensions in the Gulf. 
Read: Saudi Arabia Shows Damaged Aramco Site After Being Hit By Drones

The basis of blaming Iran for Aramco strikes

Iran was blamed on the basis of the imagery which showed remnants of the country's missiles at the Aramco sites, sources said.

The level of sophistication of the missiles clearly shows that the missiles do not belong to Houthis, said experts. Britain too believes the facts and points to Iranian involvement which the British government has concluded is implausible without authorization by the Iranian government. When reporters at New York asked whether the UK will rule out military action and stick with the Iran nuclear deal, Johnson said that the UK too will be defending Saudi Arabia like the US. When asked for assistance, the UK will make itself useful, he added. Pressed on whether this could mean Britain taking part in military action, he replied that all plans will be considered as per the requirements.
Read: Saudi Arabia's Aramco Plants Remain A Potential Target: Houthis
Read: Trump May Meet Rouhani Despite US Accusing Iran For Aramco Attacks