European countries have ruled out sending warships to the strait of Hormuz, despite threats from Donald Trump that Nato faces “a very bad future” if members fail to help reopen the vital waterway.

Germany ruled out participation in any military activity, including efforts to reopen the strait. “This is not our war, we have not started it,” said the country’s defence minister, Boris Pistorius.

“What does Donald Trump expect from a handful of European frigates in the strait of Hormuz that the mighty US navy cannot manage alone? This is the question I find myself asking,” Pistorius said.

A spokesperson for Germany’s chancellor, Friedrich Merz, said on Monday that Nato was “an alliance for the defence of territory” and that mandate was lacking.

Keir Starmer said the UK would not be “drawn into the wider war” but was working on “a viable plan”. “Ultimately, we have to reopen the strait of Hormuz to ensure stability in the [oil] market. That is not a simple task,” said the prime minister. He did not rule out any form of action but said it would have to be agreed by as “many partners as possible”.

European politicians have emphasised diplomatic efforts to reopen the strait, which carried about a fifth of the world’s oil and liquified fossil gas until its effective closure by Iran.

Italy’s foreign minister, Antonio Tajani, said on Monday that “diplomacy needs to prevail” and his country was involved in no naval missions that could be extended to the area. He cast doubt on expanding the remit of existing EU missions in the Red Sea to the strait of Hormuz, “since they are anti-piracy and defensive missions”.

The position taken by the three major European countries was striking because they had avoided criticising Trump over his decision, alongside Israel, to attack Iran 16 days ago. Soon after the first strikes, the US president said the goal of the military campaign was regime change, but the war has since become a wider regional conflict, causing energy prices to soar.

Australia, France and Japan have said they had no plans to send warships.

Trump had called on other countries to enter the war by sending ships to the strait to protect commercial vessels and unblock oil shipments.

Raising the pressure, he told the Financial Times in an interview: “It’s only appropriate that people who are the beneficiaries of the strait will help to make sure that nothing bad happens there. If there’s no response or if it’s a negative response, I think it will be very bad for the future of Nato.”

European Union foreign ministers held talks on Monday about options to reopen the strait of Hormuz but remained divided over whether to extend the remit of their small naval mission in the Red Sea, an idea that was circulating before Trump’s call for help.

Greece, which provides the headquarters for Operation Aspides, also said on Monday it would not engage in any military operations in the strait.

Israel said on Monday that it had launched a “wide-scale wave of strikes targeting infrastructure” in Tehran, Shiraz and Tabriz.

It also claimed that overnight strikes had destroyed a plane used by Iran’s late supreme leader, Ayatollah Ali Khamenei, at Mehrabad airport in Tehran. According to Israeli officials, the plane had been used by senior Iranian political and military figures for domestic and international travel, as well as for coordination with partner states.

An Israeli military spokesperson, Nadav Shoshani, told reporters that detailed operational plans were in place for the next three weeks, along with additional plans extending further ahead.

“We want to make sure that they are as weak as possible, this regime, and that we degrade all their capabilities, all parts and all wings of their security establishment,” said the lieutenant colonel.

The conflict is increasingly reverberating across the Gulf. Oil-loading operations were suspended at the United Arab Emirates port of Fujairah after a drone attack started a fire. Fujairah, on the Gulf of Oman just outside the strait of Hormuz, is the outlet for roughly a million barrels of crude a day – about 1% of global demand. Civil defence teams were working to contain the blaze, officials said, adding that no casualties had been reported.

A separate drone-related incident near Dubai airport set a fuel tank ablaze and briefly disrupted flights.

Air raid sirens also sounded across central Israel after Iran fired a missile that was intercepted, causing debris to fall near Tel Aviv. Loud explosions were heard over the Old City in Jerusalem.

In a message published on Telegram on Monday morning, Iran’s foreign minister, Abbas Araghchi, rejected the idea that Tehran was seeking a ceasefire.

“Our refusal of a ceasefire does not mean we want war,” he said. “But this time the war must end in a way that our enemies will never think of repeating these attacks or this aggression again.”

Israel has expanded its ground operations in southern Lebanon, moving troops to what it called “new locations” in its operations against Hezbollah.

The deployment follows a rocket barrage fired at Israel by the Iran-backed group earlier this month. At least 850 people have been reported killed in Lebanon, including more than 100 children.