British Foreign Secretary David Lammy visited Kyiv on Wednesday with U.S. Secretary of State Antony Blinken amid intense calls from Ukraine for it to be given permission to use Western-made weapons to hit targets deep inside Russia.

Kyiv has said it is fighting a war with one hand tied behind its back because of the limitations on weapon use imposed on it by Western governments wary of antagonizing Russia.

Scott Lucas, from the University of Dublin, told TVP World would tell whether the U.S. would change its policy, but statements made by Lammy in Kyiv indicated London was ready to give permission to Ukraine.

Lucas highlighted that Lammy had “indicated that Britain may allow the use of its Storm Shadow missiles, which Ukraine has had even before the American version.”

“And he said the reason for this is because Vladimir Putin has escalated this conflict again by taking ballistic missiles from Iran,” he continued.

Lucas went on to say London had intimated several weeks ago that it was prepared to permit use of its weapons to strike Russian territory but that the U.K. was awaiting U.S. approval.

Asked whether such a move could be pivotal for the war, Lucas replied that U.S. Defense Secretary was right in saying that no single capability would be decisive.

“But of course, we're not talking about a single capability,” Lucas said. “We're talking about combinations here.”

He emphasized Ukraine’s incursion into Russia’s south-eastern Kursk region as an important factor, as well as air defense and other assistance.

“The long-range missiles are important not in and of themselves but as part of a whole range of ongoing support for Ukraine, not only to defend itself but finally to convince Vladimir Putin that it's time to stop trying to conquer Kyiv,” he said.