The Turkish assault on north-east Syria is a disaster for the region and has dented Riyadh’s confidence in Donald Trump, according to the new Saudi Arabian ambassador to the UK, Prince Khalid bin Bandar bin Sultan Al Saud.

He also claimed his country had much more to lose than Iran from a conflict between the two countries and wanted to behave as “the adults in the room” by not escalating tensions with Tehran. He said Saudi Arabia would have further to fall if a conflict took place.

Breaking with the normal Saudi diplomatic silence in the UK, the ambassador, speaking at the Royal United Services Institute defence thinktank, said: “The Turkish assault is creating chaos. The last thing we need is another front of chaos in the region and I think we just got it.”

Asked about the US president’s apparent sanctioning of the invasion last week, he said: “We are concerned, no question. What is happening in Syria with Turkey and the pulling out the troops does not give one incredible confidence.”

He said he was disturbed by some recent remarks by Trump, describing him as “a tweet monster”, but conceding sometimes these tweets were just the president’s initial reaction.

He pointed to the US decision to send troops and air defences to Saudi as a sign of the continuing US commitment to the Middle East, but he warned, in a reference to Saudi Arabia’s rival Iran: “Who has benefited from every single disaster in the Middle East in the past 10 years ? It ain’t Saudi Arabia, for sure.”

Prince Khalid pushed back on claims, repeated on Monday by Trump, that Saudi Arabia acts only in self interest and was incapable of surviving without US support. He said Saudi Arabia had acted in world’s interest, pointing out that it could easily “have let oil prices skyrocket and made millions and millions more than it had made. We tried to control it because it would not have been good for the world. If the world gets ill, Saudi Arabia gets ill.”

The region, he added “needs more adults in the room and we are trying to behave like that. The last thing we need is to see things get out of control.”

He said: “We have been trying to be a calming player”. Referring to the surprise attack on oil tankers in Gulf in the summer, attributed to Iran, he said: “I don’t think people realise how close we were to significant conflict after the initial tanker attacks. That was really out of the blue. We did not expect the Iranians to get involved in that kind of attack. It was quite brazen.

“We do not want to be a hegemonic player in the region. Quite the opposite, if anything; we just want to be left alone. It just so happens we have two of the most desired things in the world – the holy cities of Islam, and oil.”

He denied Saudi’s refusal to mount a military counter attack against Iranian attacks represented appeasement, but said Riyadh had tried to reach out to Iran a decade ago, only to be rebuffed.

Although Prince Khalid admitted “many things had gone wrong in the war in Yemen”, he defended the initial intervention, but did not set out a plan to bring about peace, saying it was for the Houthis to come to the negotiating table. “We are dealing with people that use subterfuge as part of their political process,” he claimed.

He admitted the Saudi government’s initial response had been wild when it was reported Saudi officials were responsible for the murder of the Washington Post columnist Jamal Khashoggi last year in the Saudi consulate in Ankara, Turkey.

The episode was a stain on Saudi society, he admitted. “Once the truth started coming out, it was a shock to the system and when you are in shock, you respond poorly and part of our reaction was clouded in the craziness of what happened,” he said.