Joe Biden is about to relax the ban on Ukraine firing British Storm Shadow missiles into Russia.

The president is thinking about reversing course after learning that Russia is currently receiving ballistic missiles from Iran, which might be used in Ukraine in a matter of weeks.

On Wednesday, Mr. Biden's secretary of state, Antony Blinken, and Foreign Secretary David Lammy are scheduled to visit Ukraine to talk about Volodymyr Zelensky and the removal of restrictions.

Mr Biden and Sir Keir Starmer would then discuss changing the policy in a White House summit on Friday, Mr Blinken said, adding that the president was “not ruling it out”.

The delivery of new Iranian arms to Russia is thought to have prompted fresh discussions between the US and UK over the use of Storm Shadows.

“Russia has now received shipments of these ballistic missiles and will likely use them within weeks in Ukraine against Ukrainians,” Mr Blinken said on a visit to London on Tuesday.

“This is a threat, not only to Ukraine and the Ukrainian people, but to all of Europe.”

British government sources close to policy believe a change in position on long-range missiles is possible this week but not guaranteed, with discussions remaining live at a senior level.

Britain has been pushing for Ukraine to be given permission to use long-range missiles, including Storm Shadows, inside Russia.

However, the missiles are used in tandem with some US systems. The Biden administration has not given permission for its technology to be used inside Russian territory.

US officials argue that Storm Shadow missiles do not have sufficient range to hit Russian glide bombers, which are one of the targets Mr Zelensky has identified. The Pentagon has said it is concerned that using Western missiles inside Russia could escalate the conflict.

Storm Shadows have been highly effective at stalling Russian advances inside occupied Ukraine, including in Crimea, and Ukrainian political officials argue that they could next be used to disrupt Russian supply lines.

On Tuesday, a senior Ukrainian source said: “Kyiv understands perfectly well what topics will be discussed and why today given the intensification of missile attacks on our energy infrastructure by the Russians – as well as the data from American officials on Iranian ballistic missiles being transferred to Russia for use against the civilian population of Ukraine.”

Mr Blinken said that he would use his trip to Ukraine on Wednesday with Mr Lammy to “make sure that we have our own best assessment of what’s needed”.

“We will take that back and we’ll both inform our bosses – the Prime Minister and the president – and again, I fully expect that will be a part of their conversation on Friday.”

Both John Healey, the Defence Secretary, and Mr Lammy have said this week they will not discuss the details of talks with the US publicly because “such a debate would benefit Putin”.

Other Western allies expressed alarm about the delivery of Iranian long-range missiles to Russia.

Peter Stano, the EU’s foreign affairs spokesman, said the move “will likely assist Russia’s escalatory bombing campaign against Ukrainian civilians”.

“Such support to Russia’s terrorising campaign against Ukraine’s population will be met with a strong EU response,” he said.

The Iranian foreign ministry said that “any claims that the Islamic Republic of Iran has sold ballistic missiles to the Russian Federation are entirely baseless and false”. It said the sanctions would be met with a “proportional response”.

Sir Keir’s visit to Washington on Friday is his second since taking office in July. He met Mr Biden in the White House days after taking office, on the margins of a Nato summit.

At the summit, he suggested the restrictions on Storm Shadows could be lifted imminently, prompting celebration from Mr Zelensky. Downing Street later clarified that the UK Government’s policy had not changed.