UK and Israeli authorities are working to provide charter flights out of Tel Aviv and British nationals in the country should register their presence with the Foreign Office, Downing Street said.
David Lammy arrived in Geneva earlier today for talks with the Iranian foreign minister and European allies as the UK presses for a diplomatic solution to the Israel-Iran conflict.
The Foreign Secretary is meeting Abbas Araghchi alongside his counterparts from France, Germany and the EU as he seeks to negotiate a settlement before US President Donald Trump decides on whether to take military action against Tehran.
In a statement read by his press secretary on Thursday, Mr Trump said there was still “a substantial chance of negotiations” and said he would make a decision on deploying US forces “within the next two weeks”.
Mr Trump had previously said he “may” join Israeli strikes against Iran and its nuclear programme, but added: “I may not do it. I mean, nobody knows what I’m going to do.”
Friday’s meeting with the so-called E3 countries follows Mr Lammy’s visit to Washington, where he met US secretary of state Marco Rubio in the White House on Thursday evening to discuss “how a deal could avoid a deepening conflict”.
The Foreign Secretary said: “The situation in the Middle East remains perilous. We are determined that Iran must never have a nuclear weapon.”
Adding that a “window now exists within the next two weeks to achieve a diplomatic solution”, Mr Lammy said: “Now is the time to put a stop to the grave scenes in the Middle East and prevent a regional escalation that would benefit no-one.”
Culture Secretary Lisa Nandy said on Friday morning the White House had provided a “very clear timescale now” for the UK and its allies as they push for de-escalation in the Middle East.
She also told Times Radio: “There is this two-week window where the US is offering diplomatic talks. And my counterpart, David Lammy, is over in Geneva today with leading European figures meeting with the Iranian foreign minister.”
“We appreciate the seriousness of the situation, but we are hopeful that we will be able to achieve de-escalation and a diplomatic solution. And all of our efforts continue towards that end.”
Israeli air strikes reached into the city of Rasht on the Caspian Sea early on Friday, Iranian media reported.
Since the conflict erupted last week, at least 657 people, including 263 civilians, have been killed in Iran and more than 2,000 wounded, according to a Washington-based Iranian human rights group.
Meanwhile, at least 24 people in Israel have been killed and hundreds wounded.
It remains unclear whether the UK would join any military action, although there has been speculation that US involvement could require using the British-controlled base on Diego Garcia in the Chagos Islands.
The B-2 stealth bombers based there are capable of carrying specialised “bunker buster” bombs which could be used against Iran’s underground nuclear facility at Fordo.
Attorney General Lord Hermer is reported to have raised legal concerns about any British involvement in the conflict beyond defending its allies, which could limit the extent of any support for the US if Mr Trump decides to act militarily.
Meanwhile, two Labour backbenchers pushed for a “fresh, tough approach” to Tehran.
Jon Pearce and Mike Tapp, chairman and vice-chairman respectively of Labour Friends of Israel, said the UK urgently needed “a multifaceted diplomatic, economic and national security plan to guard against the Iranian threat and force the regime to change course”.
Writing in The Daily Telegraph, the pair called for tighter sanctions on Iran, the proscription of the country’s Revolutionary Guard Corps and a “comprehensive diplomatic solution” that “eliminates once and for all” Iran’s nuclear threat.