The commander of a British warship stationed in the Gulf said Wednesday that the Iranians "seem to want to test our determination, test our reactions".
Cdr William King of the HMS Montrose said: "They will say that our presence is illegitimate, even if we are in international waters legally. They can also launch high-speed boats in our direction, to test our alert levels." He was speaking to the BBC from the frigate.
If these actions are not necessarily unusual, their "intensity is perhaps stronger than what we have seen lately", said Cdr King. "I had 85 interactions with the Iranian forces in the last 27 days, which gives you an idea of the intensity."
He said relations between the Iranians and British remained nevertheless "professional" and "cordial".
Tension has been mounting in the region since the American withdrawal in May 2018 from the Iranian nuclear deal, followed by the reinstatement of sanctions against Iran. Further escalation has been caused by attacks on oil tankers in the Gulf in recent weeks, blamed by Washington on Tehran, and the tanker crisis between London and Tehran.
Iran seized the British-flagged Stena Impero tanker on July 19 in the Strait of Hormuz, 15 days after the Iranian tanker Grace 1 was boarded by the British off Gibraltar.
London announced on Thursday that it ordered the Royal Navy to escort British-flagged civilian ships in the strait.
"We are actually accompanying the ships registered in the UK," said Cdr King. "It's a challenge when you have to operate in an area twice as big as Wales with one ship. "Fortunately, we have now been joined by the [British destroyer] HMS Duncan."
On Monday, Iran’s ambassador to the UK hinted Tehran could release the British-flagged tanker – but only if the Iranian ship seized off Gibraltar was let go too.
Hamid Baeidinejad told Sky News: "Of course one issue can help resolution of another issue but these are two separate issues that need to be tackled separately."
"We're very keen to see the UK is doing all the measures necessary to release as soon as possible the Grace 1."
Mr Baeidinejad also accused the Stena Impero of entering the Strait of Hormuz from the exit lane, "which is against the law".
A UK government spokesman referred The National to recent statements by Foreign Secretary Dominic Raab who rejected the idea of an exchange.
“There is no quid pro quo. This is not about some kind of barter. This is about the international law and the rules of the international legal system being upheld and that is what we will insist on,” he said.
The UK Defence Ministry said the fate of the tankers was now a diplomatic issue.
Gargash: UAE stands with international efforts to secure shipping lanes
Meanwhile, the UAE Minister of State for Foreign Affairs said the Emirates stands with the international community as world powers were due to meet to discuss plans to secure the Strait of Hormuz.
Representatives from the United States, United Kingdom, France and other European states are expected to meet in Bahrain on Wednesday afternoon to discuss maritime security in the region.
Dr Anwar Gargash said on Twitter: “The international initiative on the security of the Strait of Hormuz is an explicit signal of the international community’s [commitment] towards ensuring the safety of navigation and energy of our region to the world.
“We stand with initiatives that preserve the security of the region and ones that avoid the possibility of confrontation.”