Evidence that Iran has been behind recent attacks on oil tankers and pipelines in the Gulf is likely to be presented to the UN Security Council as early as next week, John Bolton, the US national security adviser, has revealed.

Bolton has previously said Iran was almost certainly responsible for the attacks, but without presenting evidence. In what is likely to be a showdown over the US’s aggressive Iran strategy, in which Bolton has taken a leading role, much will depend on how credibly the US intelligence agencies can show the Iranian government is directing attacks by proxies.

“I don’t think anybody who is familiar with the situation in the region, whether they have examined the evidence or not, thinks anything other than that these attacks were carried out by Iran or their surrogates,” Bolton told reporters at a briefing ahead of Donald Trump’s state visit to the UK next week.

Four oil tankers off the United Arab Emirates suffered damage this month from explosions, which Bolton said were Iranian naval mines. He also disclosed a previously unknown attempt to attack the Saudi oil port of Yanbu.

The attacks on the tankers followed the sending of a US aircraft carrier and a bomber taskforce to the Middle East in response to “a credible threat” by Iranian regime forces.

Bolton said on Thursday the threat from Iran was not over but claimed there was some evidence that the swift despatch of additional US troops and assets to the region had served as a deterrent.

The USS Abraham Lincoln and B-52 bombers were sent on the recommendation of the military, Bolton said, even though in an unusual move for a national security adviser he had personally made the announcement.

Bolton also extended Iranian responsibility for the war in Yemen by saying Iran should be held accountable for the drone attacks on civilian and military airports, oil installations and shipping in the Red Sea being undertaken by Yemen’s Houthi rebels.

He said the Houthis did not make the drones, but must have got then from somewhere. “I think it is fair to hold Iran accountable without even further information because of the foreseeable consequences of giving such weapons,” he said.

Bolton has a long history of calling for the Iranian regime to be toppled, but denied that he was at odds with Trump by pressing for a policy of regime change in Iran.

“Before I became national security adviser I said and wrote a lot of things on every subject,” he said. “It is all out there. I believed everything I said at the time and I still do. I am the national security adviser, I am not the national decision maker. The policy we are pursuing is not regime change. That is a fact and everyone should understand that.”

He added Trump was quite prepared to hold direct talks with the Iranian president, Hassan Rouhani, but that Iran had to abandon its nuclear ambitions.

Bolton, appointed national security adviser in April last year, also defended the US policy of secondary sanctions designed to prevent European governments facilitating trade between European and Iranian companies. Some European leaders have said the policy of secondary sanctions turns the EU into a vassal state, but Bolton hit back saying “it is perfectly legitimate for the US in an effort to protect itself from the threat of a nuclear Iran to utilise the lawful instruments of economic power to the extent that it can”.

He said Trump, on his upcoming state visit to the UK, was also likely to raise the pending UK government decision on whether to allow the Chinese firm Huawei access to 5G networks. Bolton claimed the intelligence community was only belatedly coming to an understanding of how hard it would be protect infrastructure from Chinese state interference, adding the once perceived distinction between core and peripheral networks may not apply with 5G. He said “this is not some philosophical disagreement if it can be mitigated against”.

He said: “I am not sure this is a decision that has reached the prime minister in final form. It cannot be resolved in one meeting. We all want to make sure that we have a common understanding of what the technology involves.”

Bolton also said Trump would not be shy in expressing his support for Brexit. He said: “The president supports carrying out the will of the British people. He looks forward to the successful resolution of that process and he looks forward to bilateral trade agreements with the UK. America declared its independence once, and we made out OK.”